@Tangledfeet I think you're correct regarding the pressure, it'd be great if there was a standardised way of comparing gas suppliers costs! I also agree on the outlay! Hopefully someone will pop along and be able to offer some additional experience.I'm too new to this game to give any figures on longevity! I went for BOC as there's an agent only a few miles away and its less of an outlay - and I think I'm right in saying that BOC bottles are charged to a higher pressure?