4 fish, at least one guaranteed pair, 4 shells, and maybe some fry.  I will do my best to get 2 pairs, all 4 fish will be breeding size.

These are an awesome shell dweller! Be careful about getting these from people who just net a few fish from the tank -- the males guard the water column above the shells, so unless you're getting shells, a "random scoop" of fish will net you all males.