Programming a real economy in a world like that is tougher than it looks. You mean like supply, demand, transport, income, etc.? It's not an easy task.
Yeah, there's entire games based just around simulating that.
While, yes, it would be nice for some people to have a more in-depth economy - and nice for the game to actually have the "you can destroy an economy" features that they mentioned before....... personally, all I look for is the ability to sell the loot I find. Anything that makes this harder (like if, say, the shops just run out of cash for long periods of time; or if they refused to buy stuff because they already had some), would be annoying to me.
(sure, some "economic sim" would be nice for the people who care about that, but whatever system they put in shouldn't screw over the people who aren't interested in an econ sim. Just like it would be annoying if the system put in for people who like Stealth gameplay messed up the other players' Combat gameplay.)