Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
He has a lot of Macs but most of them are older Macs. It looks to me like a used computer broker selling them on eBay. I see a few newer machines but by and large I'm guessing a lot of them are just the right age to be coming off of a lease or something of the sort.

If you're worried, just ask the guy what his business is or why he has so many Macs.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.