Not when they want $200 for a broadband adapter for a system, or $70 for the box of a game, much less the actual game itself.
Nevermind the listing fees ebay and paypal charge to even put an item up for sale.
Even if I somehow get past that, there's still a fundamental lack of trust I can never get past with on ebay. And before you say "just buy from a trusted seller"... that doesn't really work. eBay has no system for checks and balances to even reasonably assure that you're getting what you're buying on there. If Amazon can so gloriously fuck it up for me when trying to buy from them, what hope does eBay have when their entire system is based on user-sold merchandise?
Still better than dealing with GameStop