The limit is 5K this year for "goods/service" payments for them to send you a 1099 form. Used to be 20K IIRC. It keeps coming done.
JMO, if you don't know the person well, and haven't done any transactions or know their history, I would pass on buying before sending money via F&F.
Some folks that do take PP, don't like the 1099 reporting side, still file taxes and don't need to be nanny stated into doing the right thing. Just a personal observation