It depends on which type of account you are having with PayPal. If you are having premier or business account you have to pay a few of around 2% per transaction. However if you are having personal accounts then they won't charge fee.
When I first set up my Paypal account, I didn't know any better and inadvertently set it up as a business account. When I noticed money being taken, I did some research and quickly changed it back to a personal account. Now I get to keep all of the money that comes into my account.
A personal account is fine if you only occasionally sell or buy something on eBay, etc. If you are going to do business on a regular basis, you would have to upgrade because of the $500 limit. Sure there are fees but Paypal's fees are cheaper than any merchant account that I've ever seen.
Yeah, unfortunately Pay pal do have these fees for their users. However, their fees arent as bad as others. I think if you have a personal acocunt, there is no fee. But if you have business or premier ( I have), then there are fees.