Well dude start researching about paypal, like milo said, you will not be taken seriously what so ever.
People are really serious/strict about buying on the internet. No one is just going to mail you cash in an envelope or whatever you're thinking.
It's also not all about them getting ripped off, do YOU want to be taken advantage of? If you don't know what you're doing people will easily be able to see and they won't hesitate to rip you
Start doing your homework