But where they fell short is if you actually wanted to make money like a merchant - buying and selling between the shops. I hate to draw on Fable for this, but imo Fable is inferior to TES games in everything BUT economic matters. In Fable, you could make quite a bit of money buying and selling if you were clever about it.
But it was nearly impossible to in Oblivion because prices didn't fluctuate at all between the shops - other than price differences because of disposition. But it fluctuates drastically between buying and selling an item to a shop - in fact, trying to buy an item back you accidently sold will have you paying as much as 3x for it as you sold it for!
At the very least, a buyback tab would have been nice for that, or make it not quite such a drastic pricechange.
Now, it sounds like Skyrim's economic system makes Oblivion's seem infantile in comparison - it's been implied that sabotaging a town's food supply will drive food prices through the roof, for example. So it's likely this is already fixed. But in any case, I advocate that the price change between a armor shop in one town, and an armor shop in another, should be much greater than the price change between buying and selling a helmet at the same shop.
What do you think? If you have a superior merchant system to both the aforementioned idea, and the implemention in oblivion, post it below!