It's fairly obvious. Both buying the same items, both trusting each other with a trade they can never proof of and your only source of proof is him who is a scammer. =). Why take the risk when we have reputable sellers in here guys.
So what do you propose then? Only established sellers could sell their goods and stuff in this forum? That's why we have escrow services readily available to help prevent scammers from plaguing this forum with bad trades. If we don't give a chance to new sellers who accepts escrows no matter how small the trade is, how do you think would the ecosystem be stimulated if the same sellers would be around?