I mean this in no way to dig at 1stSFG.
you don’t -need- PayPal, you just need to keep in mind that people you encounter on the internet aren’t necessarily your friends, or even acquaintances. You should conduct transactions accordingly. You receive and verify payment, then ship. You provide some manner of shipping proof / communication. This can even happen when you take precautions in person.
if you accept checks, you received them, cash them and verify they are cashed before shipping. We had a local guy get burned with a fake bank check to purchase a car. Yes, the perp was eventually caught and prosecuted, but the guy who sold the car was out of a car, money was credited but held by the bank, who subsequently cancelled the transaction. The car was fortunately not parted out and was found relatively quickly but was evidence for a while after the arrest. That was a good outcome, a lot of these result in a quick part out of the vehicle.