Wow, this thread isn't locked yet?
Smart-assery aside, when players are limited in their choices, they're naturally going to pick the most useful options. This is especially true for feats. When you only get seven to choose from, you are pretty limited in what you can pick. Sure, it makes sense for a mounted character to pick Trample, but how does that preclude and limit his later choices? If he's a Fighter, Trample is just a drop in the bucket. But as a Paladin, Ranger, or Druid, that feat slot is a lot more valuable.
This kind of thinking applies to any kind of game. When your game is centered around political intrigue and social duplicity, and more than 75% of encounters do not result in combat, what's more useful: a +2 flaming longsword or a ring that adds a +15 to my bluff checks? I know which item I'll be picking.
I think people really get hung up on the "magic item price" thing. In reality that doesn't mean anything. You can call it whatever you please: power limit, item gauge, potato chips, squirrel-to-badger ratio. Makes no difference. It's simply a gauge of relative character power. And since many adventurers adventure for wealth and glory (and since glory is sorta intangible), it would make sense wealth by, wow, gp value would be a nice limiting factor. 3rd edition designers have been saying for years that the magic item creation guidelines are just that: guidelines. Hell, Ari came in here and said it himself, though he didn't really have to; isn't the very statement written in the frikkin DMG?
So you don't want magic item shops littering the countryside? Great, then they don't exist! And you don't want players decked out like Santa Claus? Cool, double all magic item prices. Or triple them. Or remove them entirely and create your own system. Maybe you want your PCs to be schmucks always scraping for the next down payment on their bar tabs. Bam, magic items are no longer a form of currency. They are not useful enough to common folk or maybe outlawed. Hell, maybe it's a barter economy, and a gold-filigreed sword that slays demons and pants rainbows in the sky is totally useless to the innkeeper who brews his own beer and needs other crops and meats to feed his family.
I don't see how the rules in the DMG preclude anyone from making these kinds of changes. Isn't a big part of playing this game making it our own?