Hey Sam, Sorry, I could not help myself.
But the reason why the others are loling is because the offer you made was somewhat below standard in terms of private sales on the internet.
Unless some sort of deal is made between the parties, the usual protocol is that the buyer sends the money, then the seller ships.
You can make counter offers, but they have to be somewhat reasonable. The offer you countered means you do not understand the market. Ive sold used V8s at $700.
So learn to trust internet people or go do local trading instead.
The math thing is Zeno's Paradox.
And one last thing. You can criticize a man all you want. But never, EVER, criticize a man's wheel. Them's fightin words.