I often get (perhaps reasonable) pushback for this, but the level to which CPAP equipment and supplies are gatekept by the industry is absurd. They're a fan tube, a mild heating element, and a sensor, and I'm nearly certain that it would be pretty difficult to harm yourself using one "wrong" -- especially as opposed to other medical items and drugs available OTC.

Also, yes, they're pretty cool. I don't love that I seem to need mine right now, but at least I know a guy. :)