i would not say rare, but hard to catch in wild because of where they live and the depth they live in. We did a post about these a while ago i will try to find it for you! they should be form £50-£70 here in uk so that about $ 80-130. i guess. they can be breed so there should be more breedones available depending on where you are and the local fish breeders.
they live around a depth of about 20ft in the wild on a rocky face, tis why they can be hard to catch, same as the L307 and L270 they live in water at 20ft on a rocky face/cliff, near to a heat source, like a power station in int he stretch of river they live in i have 3 wild specimens, as they as far as i know not been bred as of yet! they were only redescribed recently.