For co2 the rental is around £50+ a year, and the fill, or exchange bottle is £30. You get about 40 20oz fills from one big bottle, so if you go through 1 bottle a year that's £2 per 20oz gun bottle every year.
For air a dive bottle is £100 and £3 a fill, and you'll get around 10 fills from a 12L. So to get 40 fills, you need to fill the dive tank 4 times, that's £12. If you just use that in 1 year it's 40 into £112, just under £2.50. But the next year it's 40 into £12 which is 30p per fill.
I've not costed fill rigs or gun bottles into either setup.
So in the long run air works out cheaper.
For air a dive bottle is £100 and £3 a fill, and you'll get around 10 fills from a 12L. So to get 40 fills, you need to fill the dive tank 4 times, that's £12. If you just use that in 1 year it's 40 into £112, just under £2.50. But the next year it's 40 into £12 which is 30p per fill.
I've not costed fill rigs or gun bottles into either setup.
So in the long run air works out cheaper.