--Macbrea----
How did it make your job easier? I would think it would be harder since you have to keep a sewperate list of all items personally created by the wizard.
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Don't do it this way, just take it as a "net gain" in wealth for the wizard (or the party depending on their point of view).
I think people are getting a little too hung up on making sure that everyone has the "proper" amount of wealth, and completely follows the guidelines. In any campaign I've DM'd or played, wealth distribution is pretty uneven. It's fairly normal for characters to have different levels of wealth, based on the items they've found or the choices the party has made on how to spend their wealth.
With a new (starting-above-first-level campaign), I'd give each player their wealth to spend as they see fit. If they choose to give the fighter most of their wealth to buy a spiffy set of full-plate armor, should I stop them? He ends up with much better equipment than he could otherwise obtain, but only at their sacrifice. It completely messes up the "wealth guideline" chart that everyone seems so keen on following, but I don't think it's unreasonable either.
Getting back to the wizard/feat example; the mage who crafts himself a wand ends up "ahead" in wealth. If the party tracks individual loot (i.e the wizard's wealth vs. the fighters) than it's up to him to negotiate with the fighter to get a reasonable deal. He might give it away, sell it at cost or sell it for full value - that's completely up to the players involved. In the end, either of those characters could end up "ahead", depending on the deal they make.
In our campaign, this is a non-issue. We adventure together, and pool both our wealth and expenses. A player needs something? The group decides whether or not to spend it. At 3rd level, with little wealth, my bard/sorcerer would love a masterwork lute - and could certainly buy it if the wealth was always "split evenly" - but he'd much rather see the paladin get new armor, of the rogue get a masterwork bow.