Most of the thousands of zoanthid morphs are not "named" and have the value per polyp of whatever people are willing to pay. Unless you buy a designer zoanthid from a lineaged grow then it is not really that "named" zoanthid. Everybody wants every zoa to be special and most are just as special as they look.
what ever your local market provides....I can often get no-name zoas for like 5 to 20 bucks a frag, and I don't mean a single polyp, I generally offer them in frags of like 10 or so polyps....