I've "bought" five cars on eBay, and come away with four of them.
I bought an MX-3 for £770, went to view it and it wouldn't have made it to the end of the road with what looked like a front bank HGF in progress. Walked away, transaction cancelled, everyone happy.
I bought an MX-5 for £3,500, went to view it, it was great, paid and drove off.
I bought an MX-3 for £250, knowing that it'd need trailering. Drove 14 hours, it's exactly what I wanted.
I bought a Xedos 9 for £750. Got a friend to collect it, met him halfway and took it the rest of the way. Complete shed, nowhere near as described, lucky to be road legal, didn't give a damn because I pulled the engine out of it. Car to be seen in a scrappy near you.
I bought a BMW 523i SE Touring for £1,077, having already seen it on the way past. Hardcore beater, dented to oblivion but mechanically spanky. Exactly what I wanted.
If the car isn't as described for whatever reason, walk away. You don't owe anything if it's not what you bought.