A big part of the problem is the games the gobt/ EPA is playing with equipment/ refrigerants. It is a multi prong spear. They are screwing around with refrigerants, and these require somewhat different/ specialized repair/ maintenance procedures and equipment, as well as recovery tanks and so on. It ups the costs for the companies, and they pass it to you. The gobt keeps mandating more efficiency, which is a quickly diminishing curve. THAT is upping equipment costs. No difference, really, in many ways, than motor vehicles.
The rules and regulations these people can conjur up makes the IRS look like a tic tak toe game
And then there's shipping inflation at all levels, and just plain inflation