i would like to add that was just his back gas....
for 1 dive to 52m......over the weekend he did 2 50+m dives......with stages
think you will find the gas cost of the weekend may of cost him around £150. ish +/- a bit.......
and he had less time on the bottom than the ccr divers so work that out with time spent ON THE BOTTOM to cost of the weekend {traviling B&B Food beer boat costs} you will find that it wont take long to get the cost of a unit and training back... and dont forget you can sell most of the OC stuff and put that to the cost of the ccr....
+ i could probably do about 3 or more weekends worth of diving {dill } with what he had left in his back gas....
you will probably find also that the CCR divers times where limited to being cold, finished diving the wreck, bored, worried someone would eat there pasty and not running out of gas .....{well except Jhononthesevern as he just wanted to look at his kit on the boat bench

}
you will find with today's ccr diving it can be skippers that limit most ccr divers in water times......some even want to charge more if you dive beyond 1.30 / 2h....
anyway as for cost, get your own J's and do your own mixing then tell the dive shop what to fill the air to. easy..... and easy for them...
well thats my 2p worth