A rebreather DIVE is much cheaper than the same OC dive
Take for example a weekends diving on a 50m wreck followed by a 15m drift in the afternoon, a typical day, repeated the next day
Twin 12l 232 tanks with 18/30 trimix, cost to fill approx £20 ($30), 7l 50% 232 at £6 ($10), so thats $40 a day or $80 for the weekend
Same dive on Inspiration
2 Sofnolime fill at £7 ($10) for a total of $20
1 3L O2 at £6 ($10) last both days
1 3L 18/30 at £7 ($10) lasts both days
So total of $40 for whole weekend
So once your into Helium the Yellow box is much cheaper to run
Thats quoting shop prices here, I can fill my Inspiration cheaper than that. (so cheap in fact I use 18/30 for virtually every dive). I get 5 hours of diving from each 3l fill and the sofno lasts 3 hours