[thejosh]

It's a flaw though. A user trusts that the amount that they see in PayPal ($19.95) is what they will be charged when they click accept - not $21.95 or $25.95 or $2,000.

It's different if you are having your customers type in their details, even though they hope you will charge them $19.95, and not double charge them or steal their credit card information - this is a reason why people use PayPal.

But yeah, like you said it is fraud, though a business could argue shipping charges or tax or "addon pricing" or whatever for a small amount (a company I would see doing this is GoDaddy), but larger amounts their PayPal account would probably be banned.