They vary greatly in price- but not rare- they have been in the trade regularly for the last 20 years+. I have seen them as expensive as 10 bucks a polyp, or as cheap as a six inch rock covered for 45$. Wonderful and beautiful coral- not unlike xenia though- may go nuts and grow everywhere- or may melt away one day. Trace elements and iodine are helpful, although water changes will accomplish this nicely.