Yeah, you don't know what you're really buying on eBay... you have to take the seller's word for everything and most of the time their word is worth dick all.
I got ripped off by an arsehole on eBay and it was only last week that eBay have agreed to honour my claim for reimbursment of lost funds. It's taken since March this year for it to get this far.
Sorry, my point being that comparing prices of real Sparco seats to ones on eBay is not really fair because in all likelyhood the eBay ones are not genuine.