I am a member on 9 sites like this one and have done loads of deals and only be had over once but that did get sorted.
The seller wanted me to send cash but I offered to do a bank transfer which was refused,then i was asked to do paypal which i said yes to but thought if something went wrong i wouldn't have a leg to stand on as paypal will not pay out on anything to do with guns, after 18 messages in total the seller feels this has turned sour, which is a shame but i still have my money