Welcome to shark sales 101 at most pet stores.
Cincyreefer seems to be about the only person I've run into that knows what is going on and sells sharks. Most stores don't give a **** and the really sad part is that they only make fifty bucks off the whole deal. You totally ---- over a nurse shark and come out with fifty bucks profit. You'd have to give me quite a few G's before I'd do that, and even then I'd probably not do it.
I watched a guy buy a nurse for a 55gal about two-three months ago. He then said, "don't worry I'm upgrading to a 125 soon" wtf is that? The store still sold it to him.