Got a deposit on a car, how long do I wait to relist?

[hh76]

I'm selling my old pickup ($1200), and the second day it was listed, someone bought it. Well, kind of. He came alone, and didn't have any way to get it home, so he left me $200, and said he would call me when he knew what time he'd be back the next day. Normally I wouldn't do that, but I was sick of answering questions from potential buyers, and just wanted to be done with it.

Now, it's 2 days later and I haven't heard from him. I called and left a message, but nothing. I still have the truck, and the title. We never discussed a time frame, or refundability of the deposit because I actually believed that he'd be back.

How long do I have to wait until I start listing it again?

If he calls back after I sell it to someone else, does he get the deposit back?
In my mind the whole idea of a deposit is some sort of guaranty from the buyer, so if it were refundable, what's the point?

I'm thinking I'll call him one more time and leave a message telling him that I'm relisting this weekend, and it's going to the first person who shows up with money. If he wants it and his deposit, he'd better be that person.