$60 sounds expensive to me. I used to see them for $30 CAN! Exotic, yes. Cool, yes. Unfortunately, extremely short lived. One of the more short lived of the cephalopods. When you buy one, it may already be near the end of it's life cycle, and may last less than a month in your tank. $60 for a month seems a bit pricey when you think of it that way.
Price varies widely, that is not bad, but as pointed out, they only live 12 to 18 months and one with a 6-8" tentacle spread is already an adult, it is an interesting toxin that is fairly easy to preserve though so if that kind of thing interests you and you are very careful it might be worthwhile.
Are cephalopods so short lived in the wild? I know the giant octopus can get old but do the small ones have such short lives? If not, it seems cruel to try and keep an intelligent animal knowing that it will inevitably die. If not, go for it, I guess.