I remember tinkering with the toolset when I first got into the game and there being a setting to limit the number of items available in merchant shops (1- infinity). If this were set to some finite number for all goods, I think that might improve the "survival" feel that so many people have been arguing is lacking. I'm not sure if setting the number to less than infinity drags the engine down or loads a bazillion inventory pages for the merchant, but it's an idea.
And yes, I know it would make it harder for newbies to get established - that's the whole idea. Even "rich" characters could get into trouble - "oops, Bunge is so sorry. Out of medicine bags and potions am I".
Food for thought.