I’m a frequent purchaser on Swappin & Sellin here and I prefer to use paypal. I don’t use friends and family though, just the regular transaction, from which paypal deducts fees on the seller’s end. In appreciation for sellers here allowing paypal payments, I always offer to pay those fees.
When the seller gets his money, paypal charges a fee of 2.9%, then tacks on another $0.30. I reverse this to make my calculation. Here’s how the calculation goes.
Say the seller wants $79.50 for his item. In order for him to receive just that amount, I add $0.30 to get $79.80. Then I divide that by 0.971 (same as 100% minus 2.9%) to get $82.18, the amount I pay on my end.
This works for US transactions, not involving foreign currency. I thought y’all might want to see the process. It's slightly more cumbersome that simply adding 3%, but it's accurate to the penny.