I feel that I can very easily justify the cost of an Rebreather. When doing trimix dives OC, I average about $45(all monies in US currency) an hour in gas. This doesn't even account for the cost of fuel for me to drive after every dive to get gas. For CCR, my calculated cost for sorb and gas is $10/hr($4 for sorb, $6 for gas). I don't account for batteries, O2 sensors, disinfectant, etc....because the fact that I will have less than half the number of regs and tanks to service makes up for that. I figure that, based on a total cost of $10,000(RB purchase and all training costs), I will have the RB paid for in 285 hours of use. That's about 1.5 years for me.
The other big reason for me being able to justify an Rebreather is the safety factor. If the brown stuff hits the rotating cooling device while I'm way back in a deep cave, assuming my RB is functioning properly, I have lots of time to sort it out. That time would be 8 or 10 times(at least) what I would have if OC. There was a double fatality last June at a cave called Eagles Nest, about an hour north of Tampa, Florida. IMO, if these guys had been on CCR, it would have been a scare instead of a double fatality. (Link:
http://www.iucrr.org/20040612_01.htm).
I have a lot more money wrapped up in other hobbies than an Rebreather costs. I have almost $20k wrapped up in skydiving gear(3 full skydiving rigs, lots of specialty equipment including digital video and still cameras). I have more than I want to think about wrapped up in my airplane.....and I'm currently looking at buying a helicopter, which is even MORE expensive!
The bottom line is that this is a hobby for most of us. We make the choice as to what we are willing to spend on such hobbies....and we live with it(and enjoy it immensely).
Mike