i believe i may [should] have the most expensive Ntwo in America because i'm at the end of the supply line; Hi.96743
Air Liquide is global supplier of Gas & COtwo for restaurants etc. They Are Everywhere.
I get their 445cuft 6000psi tank delivered to my door full for $233- [rent free 6 months, 9/mo after].
they also supply Ntwo to the local brewer, for a slurpy local treat.
My tank will fill an Mrod 463 times before it fades below 3Kpsi, about .50 cents per
that would take 46.3 trips to the diveshop for 10 fading fills off a single 3000psi scuba bottle, w/ only 1st at 3K.
the initial setup is the only cost you can compare; the fittings, hose gauge & regulators are $500-
[same as a shoebox, or a single 4500psi CFRP bottle before any hardware. and good luck finding a fill] .
after that its remarkable what else you DONT need to buy,
There is nothing to break or plug in or wear out or turn off on time or wait to fill, or filter for moisture or fan to keep cool. no parts.
just unlimited dry gas that wont expand and stretch your seals or allow any moisture.
and you can leave it out and tied to a tree, for best maintenance practice, someplace the backhoe wont go.