Ah, i kno how this goes. what i do is when someone says that the'll do it, tell them it's still for sale unless u give me the tracking number on the MO/check etc. than if someone says o, i got the money, but doesn't for another month, and someone comes a week later and says i can get an MO by tomo, u can tell the other guy ur taking to long, and take the other MO, first come first serve.
Best thing to do is set deadlines. say he says i'll buy ur xx. it's monday. send him a mail saying how long till u can get a MO/check w/e. if he says, o i can get it wednessday, send him an e-mail saying that u need confirmation that it sent by friday. keep good communication about what's going on, and if friday comes and it doesn't ship, tell him it's going back up for sale, and if someoen can get the money sooner, than first come first servered. i've never had a deal go dead after them saying they can get the money, and i always let the other person how long it'll take b4 i can get the MO.
Feedback also helps
unless of course i'm totally wrong than forget everything i said