I'm not saying he's necessarily a scammer, but scamming people out of relatively small amounts is exactly what the crooks do at least around here. They get a lot of individual, rather small payments out of a lot of different people, because that way the cops won't get very interested in minor frauds and they can go on for years and years without facing any real consequences. We have plenty of examples of those cases, and a couple of my friends have been fucked exactly like that. One of the most well-known scammers around here tried to rip me off for a $200 cab a while back, and he's still out there doing it.
Again, I'm not saying this is the case here, just commenting on the "small amount" thing. Be careful with the smaller trades, too!