At the end of the day does it not boil down to leaving the choice with the buyer? i.e. if they feel they need the reassurance that the sender will send and the Post Office won't lose it they can pay paypal transaction fees.
If paypal 'gift' is simply banned it suggests that members cannot be trusted on the one hand and on the other those untrustworthy members will continue in a very trustworthy way to swop and sell between themselves by email..leaving paypal, classifieds and buyers out of the equation.
A lot of assumptions in this statement ,certainly not made by the forum.