Magic items are things you earn, and are granted by the GM, so most people feel a little different about that than they might about things that are a little more easily considered in the balance scheme of things (IE, hard character rules, not items that can come and go).
I don't think external balancing should occur on magic items for just that reason. It's not going to be popular to say to a player "You have too many magic items, you need to lose one" after an adventure. It may suck for a player who's on the other end of that scale, but my experience in living games is that it does tend to balance out over time, though the 3E vs 4E mechanic for it may varry a bit.
As for economics, I'm pretty easy going on that, but I think the big worry is that you mention the tavern. Since the Tavern is an off screen between adventures kind of thing and there is often little control about how long you're there, making people pay for things there is a bit unfair.