As I see it, your question is about industry; what goods or services can an Antarctic town produce in order to trade with other communities?
Realistically agriculture can't happen there, certainly not on a competitive scale and most production would be designed to feed the locals, not produce an export market. That really leaves you with 3 options.
As I understand it, there are a lot of mineral resources in Antarctica, although I don't have specifics to hand. This is however more problematic than you may think. Antarctica is protected by international treaties that prevent exploitation. The minute one country violates that agreement, the others swoop in, and start digging up this pristine environment. That could be a problem for the ice for one, and that also means that there could be environmental impacts.
At present, most settlements in Antarctica are there for research purposes. Let's say (for instance) that one of these settlements declares independence and sells research time in their settlement. This research would be an industry; sure. BUT, the problem is that scientists are a frugal lot (research grants don't spread as far as you may think) and if another area of Antarctica is still controlled by its owning territory and is prepared to support scientists more or less for free, they'll all go there instead.
This to me seems like the most viable solution. There are a lot of people who'd like to visit Antarctica, take tours of the place, see the old research outposts, etc. Extreme tourism (dangerous because of the cold), eco-tourism (last pristine environment), even historical tourism (the Mawson, Scott, etc. expeditions) could all be accommodated. This type of industry is even the basis for Kim Stanley Robinson's novel Antarctica.
So there are options, tourism being the most practical and viable, but as to how viable, it would depend on the size of the town, how many resources (as a percentage) they can dedicate to this industry and how much external 'stuff' they really need to keep their home environment in good repair.