I once had someone initiate a chargeback over 5 transactions of 10$ they paid via CC. It ended up costing me 100$ because on top of the 10$ they charged back, every transaction also added a 10$ fee for being charged back. So I was scammed, and then had to give paypal 50$ for it on top of that.
Are you sure those were from PayPal? I've been charged those fees, but they were passing on the fees from the credit card company that the payment came from.
Well, that could be the case. Either way, someone sent me 50$ and I ended up losing those and paying another 50$. That shouldn't really happen when you just have a private paypal account. This wasn't a commercial transaction.