OT: Various Paypal percentages..........?

[beamrider]

I see many people selling things in FS/FT, and they say to add XX% if using PayPal. My understanding is that PayPal charges you 2% of the amount. Why is it, then, that I see people saying add 1.5%, 3%, 5%.......? The 1.5% I can see, as the seller basically bites the other .5%. But 5%? Are they trying to make money off the actual paypal transaction or something?