I'm outlining some ideas for a game I'd like to write, that at its core is about interplanetary space-trading (amongst other things, but that's not relevant to the question).

For project-scope reasons I don't want to go down the route of implementing planetary landings, and want the entire game to occur in space. For this reason when the player will pick up or drop off goods, it's entirely done at an orbiting space station. Now, the commodities eventually have to end up on the planet surface anyway, so why would all trade occur in orbit rather than on the ground?

Similarly, goods that are exported would have to find their way up to the orbiting space station to be traded. This seems excessively expensive.

If the space-ship in question were massive, it might make more sense as the cost of getting that thing off the ground might be impossible. However, I envisage the player to be in a smaller space-ship (think: Firefly), and not some behemoth of a transport.

I am looking for "as real" answers as possible. My ships won't have magical shields, and I'm trying to keep it as close to reality as possible - only cutting corners where there is literally no other way of achieving something.

Thanks in advance!