I've never heard of counterfeit K701, K702, or Q701, so I wouldn't expect them now with such a specific headphone as the K702 65th anniversary.
If the ebay seller looks like a legit audio dealer that's another reassurance. If the deal is too good to be true though, then you should always be on guard no matter where you're buying it.
Alright, I will probably pull the trigger. The price is the same as Amazon's listing at ~$430.