Actually no, if you want to create new account you need to pay a fee, from same IP though, but I doubt you or any one else could stop people from selling their accounts.
But I'm with you about scammers.
That's not completely true. You're only forced to pay a fee if you sign up through Tor, or on an IP address that an account has been banned from before. If my memory serves me right, you'll also be charged a fee if you sign up from an address similar to one that has been banned before. (ex. if someone has been banned on 1.1.1.1, and you sign up from 1.1.1.15, you'll need to pay a fee, but the fee will be smaller than that of signing up from 1.1.1.1) But I'm with you about scammers.