They occasionally show up at the larger shows and sometimes are up for rescue, tho not often enough (since that's one of the only ways I'll be able to get one). Most often, they are placed in rescues because the owner didn't realize how much room they needed and didn't want them anymore, or more commonly the skink lost a few toes and the owner gave them up. Toes are quite fragile on these guys.

I wouldn't trust that guy, personally, with what you've said he told you. Instead, go visit Bluetongueskinks.net and talk to some of the breeders there. The prices aren't much higher than $100, which seems to be a basic BTS price, and they are highly acclaimed from what I hear.