Honestly I don't care if I get anything for them, my LFS gives me so much free stuff I consider them a donation. The lady who runs it has given me enough marine salt to get my brackish tank started until she could get more small boxes in stock, she gave me my crawfish, some little catfish fry (none of them made it, in my tank or hers for very long, bad batch of fry), every guppy fry she had in her tank when I got my adults (they didn't survive the week or so they were left in our roommate's care, sadly), and countless snails for feeding my puffers (ramshorns, pond snails, and some really nifty white ones). She also held onto the tank I wanted for a couple months until we could finish paying for it, despite many people with cash in hand asking about it. As for the cray eating them, I don't mind. She very rarely grabs one. Most of them just swim where she can't grab them and there's lots of cover in the tank. She's worse about grabbing the ramshorns, actually.