To be honest I don't see what the problem is.. If you have a lot of snakes that you need to sell at a pretty damn decent price, I wouldn't want a lot of random people just asking for a picture or multiple pictures. This guy is doing a great thing to keep down inquiries who aren't serious. Personally, I believe all breeders who sell multiple snakes at once should do this. Have two or three good pictures, and if someone asks for more, charge them. If I'm serious about buying a snake, I'd be willing to pay the dollar (IT'S A DOLLAR) whether I was getting it back or not.
I'm a Great Dane breeder and (even if you don't much about about the dog breeding world), my females can give me about 10 to 13 pups a litter. I don't have time to be sending pictures to people who aren't serious over and over again. It's frustrating. I might implore his idea to cut back on people window browsing. Especially if I get a really nice looking Harlequin, people will inquiry about that one pup 20+ times, and me being nice, I'll respond and give them a picture, then I never hear from them again.
I'm into snakes and large lizards, too. But the dog one was the best I could think of as an example.