In economy, a planet can be defined as a lot, or a property, or a house, or a land, or more likely, all in one, on a much bigger scale.

When we are talking about buying and selling an entire planet (assuming it is possible by the law background of a given market), and thus a price goes into consideration, what kind of values contribute to it?

DO NOT TAKE EARTH INTO ACCOUNT IN THIS CASE! Earth owns such a huge intellectual inner value (cradle of humanity, etc.) that becomes literally priceless, a.k.a. impossible to determine in capitalism.

Some items I can find out by myself:

  • Ratio of habitable land
  • All kind of natural resources (minerals, ores, flora & fauna, etc.)
  • Artificially added material value: infrastructure (plants, plumbing system, telecommunication, transport & logistic stations, storages, etc.), lots, houses, factories, shops, other business facitilies
  • Inhabitants' income: personal level, local market level, macroeconomical level (~GDP).
  • Historical sites, artifacts, etc.
  • Immaterial value: role in galaxy scope (e.g. transit station, tourist location, etc.)

Did I miss something?

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    $\begingroup$ Asking for a list of everything that would go into determining the monetary value of a planet would seem to be too broad because the set of answers is potentially unbounded and no one thing is likely to make an answer "more correct" than any other answer. $\endgroup$ – a CVn Mar 21 '16 at 10:03
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    $\begingroup$ @enkryptor You make a valid implicit point, namely that owning land does not make any sense. However, most legal systems on Earth still permit owning land. By extension, if the nonsense of owning land on Earth can be legally recognised, one could apply the same to extraterrestial land, including entire planets. $\endgroup$ – gerrit Mar 21 '16 at 11:12
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    $\begingroup$ @enkryptor Government controls whatever land they lay their claim to, violently or otherwise, with or without recognition by other governments. Whatever works on Earth also works elsewhere. $\endgroup$ – gerrit Mar 21 '16 at 11:32
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    $\begingroup$ "Greetings to you. This is a recorded announcement as I’m afraid we’re all out at the moment. The commercial council of Magrathea thanks you for your esteemed visit, but regrets that the entire planet is temporarily closed for business. Thank you. If you would like to leave your name, and a planet where you can be contacted, kindly speak when you hear the tone. [Bleeeep]". $\endgroup$ – MichaelK Mar 21 '16 at 12:03
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    $\begingroup$ @beppe9000 You can't sell what you don't own. The Outer Space Treaty applies: "outer space, including the Moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means". Most of the countries that aren't signatories to that treaty are in Africa. $\endgroup$ – a CVn Mar 21 '16 at 12:26

What does 'buying a planet' get you?

For nontrivial possessions, a significant factor in market price is the set of rights (both de iure and de facto) that you get by 'buying' it.

For example, real estate grants you (mostly) exclusive rights to use and develop it - but the price is significantly affected by the extent of those rights. For example, in our current world:

  • Are mineral rights included with the sale? Will the government in that place impose a 'resource tax' taking half of the value of the oil/diamonds/whatever produced there?
  • Will someone enforce your rights? In particular, if others start exploiting the land that you bought, will the government or seller enforce your rights, or have you simply bought a paper that says that they won't interfere with you, but it's your own problem to actually claim, enforce and protect that land?
  • Are there any limits to the exploitation? Suppose the land contains an important and valuable transit route; are you allowed to take tolls/taxes on that traffic for crossing your land or is that traffic free to cross? Even more, maybe there is a duty for the landowner to maintain that route at their own expense while letting the traffic pass freely (e.g. medieval bridge maintenance in some parts of Europe).
  • What about the current inhabitants? Are you allowed to evict them or charge arbitrary rent?
  • What about limits to allowed activities - owning a nice plot of fertile land is rather useless if it has been designated a nature reserve where farming is not allowed.

This goes double for buying planets.

  • Do you get unrestricted rights to all natural resources - can you strip mine the whole planet if you want it to?
  • Do you get autonomy/independence - i.e., can you make your own social laws without interference "from above", or do the people on that planet have the rights granted by some other government?
  • How about current inhabitants - are there any, and what rights do they have after you've bought their planet?
  • If the planet exploitation gets de facto contested, will you have to (re)conquer it yourself or would buying it also buy the enforcement of your rights there?

All these factors will change the value of 'buying' planets significantly, simply even if the planet is the same, you're buying very different things depending on answers to those questions.

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  • $\begingroup$ I think this is the closest to what I expected as an answer: goes into conceptual issues instead of specialized ones, and considers issues I forgot mentioning. $\endgroup$ – Katamori Mar 21 '16 at 12:23
  • $\begingroup$ Also as I mentioned above, how the buyer intends to use the Earth (investment, reserve of natural resources, market, or industrial base) will change their perceived value of the planet as an investment. Some stocks are valuable for their earning potential (aka Google or Apple), some for current earnings (e.g. blue chips), and others are valuable for their assets (e.g. railroads). $\endgroup$ – Jim2B Mar 21 '16 at 15:42

The factors involved in determining the market value of a planet are quite vast in their scope (and thus be dismissed as "too broad") but I would provide a short overview for you.


This is a very important concern if the buyer intends to build a colony (of living beings) on the planet. Planets located inside the habitable zone would come with a much higher price tag than those located too close or too far from the parent star.

Also, for research purposes (setting up unmanned research labs on the planet) other factors come into account. For example, some buyers (groups or individuals) might be more interested in a pulsar planet (a planet revolving around a fast rotating neutron star) than a habitable planet. Others might be interested in planets revolving around white or red dwarfs. Last, but not least, planets revolving around a red giant might sell for an exorbitant price, provided that red giant phase of a star is a very limited time (as compared to its total lifespan).


This is another very important factor. Is the planet terrestrial, gas giant, gas dwarf, water world or ice world? In case of not being a gas giant/dwarf, does the planet have an atmosphere? If the planet is terrestrial, what is the composition of the crust? What is the atmospheric composition (in case the planet does host an atmosphere)?


Size can be a tricky thing when determining the planetary price. For small scale buyers, small rocky worlds with large amounts of precious metals (precious being a very subjective term) would be much more valuable than huge gas giants. On the other hand, if it is a gas giant with massive amounts of fuel gases (such as methane or acetylene), it would fetch a better price for civilizations interested in space travel, inter-planetary trade etc.

NOTE: size refers to the mass of the planet, not the volume. Also, most customers would require you to provide a gravity (free fall acceleration rate) index of the planet.

Moons And Ring Systems

Another important issue would be moons. How many moons does the planet host? Are all moons in stable orbits around the planet? If not, are those (unstable) moons drifting towards the planet or away from it? Does any moon allow the building of tourist resort? Does any moon allow habitation and settlement? Does any moon have precious metals? Ring systems would be of special interest to interplanetary tourism companies.

NOTE: In case there are some moons with highly prized features, the seller might want to withhold that moon from the deal and sell it as a completely new deal!


Probably the most important feature for lonely civilizations such as us, humans, who want to discover and communicate with intelligent beings in our neighborhood.

Also, some companies might want to purchase a life-hosting planet in order to experiment panspermia (to take some primitive life forms from one planet/moon and release them on other planets/moons in order to study evolution or provide dinosaur hunting safaris or whatever).

Last Word

There are several other factors involved in determining the price of the planet. But considering that too broad and TL;DR answers aren't welcome here, I would suffice with the factors listed above.

In the end, remember one last thing: in any market, price is determined by demand.

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  • $\begingroup$ Another thing determining the cost is the desired delivery speed: willingness to wait a regular amount of time for a product will cost less than wanting an express delivery (as in: courier services). $\endgroup$ – Thomas Jacobs Mar 21 '16 at 9:46

What is the market price of anything? What people are prepared to pay for it.

If the planet offers nothing of valuable then people will pay nothing.

If the planet holds some unobtanium material not found anywhere else then they will pay anything.

Most planets will fall somewhere in between but the point isn't to have a list of potentially valuable things. The point is to work out how much someone is willing to pay.

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    $\begingroup$ Yes, that was an obvious answer, because this is the very basic principle of market economy. But people judge this willingness based on internal values of a product. As you can see, I listed some, is there anything else beyond these? The choice of title was to make it more understandable. $\endgroup$ – Katamori Mar 21 '16 at 9:30
  • $\begingroup$ @ZoltánSchmidt That question would most likely be off topic here as you're just asking for a list of potentially valuable things. $\endgroup$ – Tim B Mar 21 '16 at 9:39
  • $\begingroup$ I don't know, these can be considered in worldbuilding, so I don't think so...this hobby involves a lot of other fields of knowledge. $\endgroup$ – Katamori Mar 21 '16 at 10:05
  • $\begingroup$ @ZoltánSchmidt The problem is that it doesn't work in this format, in that we can't rate different list answers against each other. Asking for techniques to evaluate planets would work better I think. $\endgroup$ – Tim B Mar 21 '16 at 10:07
  • $\begingroup$ True, but as far as I can see, there are decent answers anyway - answers different enough for this issue not to appear. $\endgroup$ – Katamori Mar 21 '16 at 10:16

There are also the factors which have nothing to do with the planet itself:

Economics of the galactic system. Doesn't matter how "valuable" something is, if no one can afford the high price, its value comes down.

How many competitive bidders? The value can change vastly depending on whether there is one unopposed corporation looking to buy it as opposed to several who might be competing for it.

Could the Vogons impose a compulsory purchase order?

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