hi sadie
it is my belief that the "blue" morphs are not that rare. the candie i own is one, however it is not a true blue imo. i find that coral color is very dependent on light color. my "blue" candy definitly isn't green but its not blue either. if the one your looking at looks blue to you buy it, but be advised its color in your tank will be based on your lighting and may change in a month or two????????? as far as price if its at an lps you'll pay 30 + for it ...... i got mine as a frag from another hobbiest for 15. By the way hammers also have what is called a blue morph and the same applies to them.