I can't show any specific evidence, but... You just can't get a $499 product for $325 unless it is used, hot, or not as described.
The eBay auction says "Condition: new" It doesn't say anywhere specifically that it is brand new, unopened, with retail package, or whether it comes with ATI's 3 year warranty.
Their privacy policy, conditions and legal notices pages are broken, which worries me a bit.
All of their feedback ends March 2004. Yet they currently have 184 products for sale. A gap of over a year on feedback is an indicator of a possible hijacked account.
However they are Better Business Bureau members with a satisfactory record
http://www.orlando.bbb.org/codbrep.html?ID=140953989&cons=y