So maybe it's a toss up. But I still agree with the original poster: The guys with the least amount of post and least feedback should consider shipping first to prove his honesty if the buyer requests it. If they don't want to fine. I was recently looking at a several hundred dollar amp, but when I saw 30-something posts and it took the guy four days to respond, I said to myself "No way...." I considered asking them to ship first, but since that's not the way its usually done, I didn't bother to ask. I lost an amp, he lost a sale. If there was the "ship first" option, we both might have won.
Ideally, someone should volunteer (or be paid) to be Mr. Head-Fi Escrow. Someone who gets the money and when the amp comes to him, ships it to the buyer. Then the seller gets sent the money.