Not Mars. Too far away, not enough resources. Call it the Moon. Luna, with the aid of some technology, that existing, anticipated, and theoretical, could be self sufficient in everything but nitrates for fertilizer and for the air mix. Everything else, O2, H2, H2O, most metals, phosphates, calcium, and silicates can be acquired with a little high technology (I can explain some of it if you want).

However, as for the economy and such, it's anyone's guess. There would have to be some kind of trade, at least for nitrogen (essential for plant growth in the form of ammonium nitrate, potassium nitrate, and similar chemicals, and an important part of breathable air) and for technology products, as well as supplemental hydrogen fuel. Aside from that, you might as well try to predict the weather where you are now at this time in fifty years. You could make educated guesses, but you don't know.

A good look at a plausible scenario can be found in Robert Heinlein's story The Moon is a Harsh Mistress. That might give you some ideas. But really, I don't think we can make any useful predictions.