I've got probably 60-70 assorted ceriths, nassarius, trochus, astrea, margarita, and an enormous turbo that won't die. three fighting conches, a serpent star, a lettuce nudi, and 3-4 hermits that have been around forever
A lot of my snails are pretty small, especially the sand dwellers... so maybe that's why there's such differing opinions on the number you should have.