What to do with people who back out deals

I don't know your conversations. But I'm betting there is the other side of the story also. I would point out, that in your statement alone.
You seem to have taken your time "hours" to make the payment. Maybe, just maybe he felt like, within your conversations, you were going to make a more immediate payment. When you didn't. He sold it to someone else.

But, correct, not cool.
He sent me the wrong pay pal address. He sent the correct on at 11:00PM. I am asleep, I see it the next morning when I am at the hospital with my wife. By the time I get home at noon he already sold it. He had my phone number. Pretty crappy I think. No delay on my part