Ive been selling items online via Gumtree for a while. Occasionally someone wants me to post an item(and Im happy to) but then want to pay via Paypal. I researched it and found that they take 2.9% of my sale price and a process fee as well, but it appears the buyer doesnt have to pay anything to use the service. Its quite difficult to understand all their terms and conditions on their website.
From my research Ive found that its also quite common for buyers to either use a hacked account or claim they never received the goods and charge back the money. They appear to always favour the buyer over the seller(who is the one who paid them in the first place!).
Now that Gumtree is closely associated with Paypal its becoming more of a problem for me, which is ironic given that Gumtree state their all about face to face, local sales and they advise against posting and paying online.