thought on eBay?

I've bought and sold things on eBay, but never $$$ audio equipment. I have had good experiences with Audiogon and AudioMart but I'm cautious about eBay, if only because many sellers often have little history with audio gear. I'm looking at an item that will likely end up in the $4k range from a seller who doesn't accept returns and has almost no record of selling audio equipment but does have an extensive and excellent record of buying and selling other things. 

1) In general, would you guys spend many thousands of dollars on eBay if there are no red flags--or do you say "never eBay" for big purchases?

2) Can anyone explain the reality of eBay's policies? I can see the "money back guarantee" if the item arrives "broken, damaged, or faulty." But I've also heard plenty of horror stories out here about companies that offer similar guarantees in theory but are awful to deal with in reality. I'll add that sometimes "faulty" for stereo gear can be a vast grey area.

So, bottom line: would you make a big audio purchase through eBay, especially from a seller with little visible audio experience?