Um...

1. There's currently no policy that says you can't sell the usage of items that you find in Blizzard's game.
2. There's no policy that says you can't play extended amounts of time.
3. There's no policy that says you can't sell things on Ebay.

Using facts 1, 2, and 3, I see no problem with the IRS in this situation. At worst, you have to report it as taxable income (which would be about... $12 per $100 you make I believe).

What is it they say about silence being golden?