Screwing Someone

what about this:

via msn you agree with someone to buy or sell something for $$$.
you agree to pay afterwards.
the box you send out or receive says "gift worth $30" or something so you won't have to pay taxes.

now if one of the parties doesn't pay.. can the other one f*ck him back or are they stupid.

I dont understand

Well I don't know much about law but as I see it there was an agreement between both parts and there's proof of that agreement in both persons message histories, so I'd say that the person who didn't receive the money has a case

who gets something first before they pay? I wish shops do this, ill pay you later yeah? *runs*

If you're worried about a transaction, use escrow.com

If you're trying to screw someone, don't