you need to go through your pay-pal site and read the fees/usage pages- some transactions have fees attached- others do not- my mother pays me her phone bill each month with paypal- if i send a request there is a fee- if she just sends me the money there is no fee-
if she were to set it up for a re-occuring payment to be paid each month there would be a fee-
different transactions have different fees and rules- and you should be familiar with how it works-by reading all those pages they sent you when you signed up....which you also signed and said you understood.