I had one today. I use a CPAP machine, and the masks you use with them are a prescription item. I thought I had to go through the medical goods firm that my insurance company recommends - and they charge me, until I've met my deductible, aprox $400US for a mask kit. Exorbitant, but I was OK with it - thought that was my only option, service was reasonable, etc. Then I had an issue with something being billed incorrectly, and they got very snarky with me. So I started looking around. Found that I could just buy the masks, without the insurance, for less than 25% of what I was paying. Thought I'd check with the DME and see if they would price match - after all, I'd be saving myself $$$ and my insurance company $$$ - they pretty much told me to pound sand. So I bought them from a wholesaler instead of through the insurance people.
Shame - we'd been buying $$$$$ from the medical goods firm since DP got out of the hospital, and will continue to buy $$$$$ from someone - but I don't think it'll be that company, after the way they treated me. I mean, tell me it's not possible, that's one thing, but to be snarky over their mistake and then over a simple, routine request?? No thanks.