No dont sell to the pet store. If people start buying them and they are careless, these can reach local waters. These crays are capable of destroying an ecosystem with the way they breed. They would become an out of control problem.
When buying marble crays you have to be very responsible and have a way of disposing them properly, like feeding them to your fish.
I am pretty sure in time these particular crays will be illegal because they will get in the wrong hands and they will end up getting loose in the wild.