Since that price is half again as much as my CAR cost, I think l'll pass. And I agree he's probably missing the boat doing it that way. Probably doesn't want to sell to a dealer, as he probably wouldn't get his price.
They say Rome wasn't built in a day, and you couldn't have destroyed it one day, either. He surely bought all that stuff piecemeal.
But for the sake of argument, let's say he bought all of it new and has taken good care of it. Leicas, Canons, Rolleis, some good stuff there if it's all in good condition. But it would take some time to be sure of that. (What's his buyer feedback???)
He surely would do better, and probably get more total, if he would go one at a time, or at least similar things at a time. We don't know, but could it be that he DOESN'T HAVE the time, if you know what I mean. You'll surely see the same ad a few more times.