I think people overstate the interaction between gold and the magic item economy. Lets look at this in detail:
1) You cannot make items beyond your level.
2) You cannot make items that are uncommon or rare without DM cooperation.
3) Even vast numbers of at-level consumables won't break the game.
4) The DM has total control over what items the party can buy.
5) Higher level items are VERY expensive.
So, imagine a party with limitless gold. What can they do? They could craft a whole pile of at-level common items, which consists of basically vanilla magical armor, weapons, etc. These are useful items, but equipping every member of the party with these items is going to have only a slight impact on power level, especially given that the game already supposes that the PCs have level appropriate equipment. Usually they will already have items better than what they can make anyway.
Lets suppose the players decide to make a whole raft of healing potions. This won't help them a whole lot either. At some levels a potion is a bit better than just spending a surge, but in combat they require a whole standard action to use, making them marginal at best. Outside of combat there are a ton of other ways to get better results than a potion, even for a 1st level PC (which is the very best case for a potion).
There are a few other consumables that might be pretty useful if you could have limitless numbers of them, but all of these require Enchant Item to make, and very few of them are common. Even the best of them require actions to use and have only modest effects (imagine a party with heaps of whetstones, magic arrows, and various potions). The cumulative effect might actually be moderately impressive, but within a level or two these items will be basically sub-par and not worth using anymore, and more appropriate items will be multiple times more expensive.
So, there's effectively no reason to care about how much gold PCs have available to them. You can safely give them whatever amount you feel like they'll be able to have fun with. The real question is just how you motivate excessively rich PCs, and the answer obviously is that wealth should be at most a marginal motivating factor in most games. If it IS a huge motivating factor then just don't go overboard. Even a pretty oversized chunk of treasure will shrink to insignificance in a couple levels.