I wouldn’t compare fitting a CPAP to fitting a hearing aid.
You are correct. I would say fitting an APAP is much easier than a HA. In fact a good APAP right out of the box will work for most people in a basic fashion. They almost always can be improved after data is collected and the machine tuned for the user’s particular condition and needs. It is quite reasonable to buy an APAP on line and set it up yourself. Many do.
The HA looks far more complex and I see that some actually do set up their own. Without specialized measurement equipment that would seem difficult to do well. My point was that the amount you pay for the service does not always get reflected in what you get. I suspect some get great after sale service, and others do not. I am not too worried about Costco because if worst comes to worst, I will just return the thing, and start over somewhere else, perhaps a bit wiser…
I have not dug very deep into the DIY side of HA’s, but from my initial look there seems to be an obvious gap in adjustment ability to suit the user. Adjusting the frequency response curve seems very specialized and should not be messed with by someone without the precise measurement equipment. But, other things seem to be just basic setup of options; on/off, level 1, 3, or 3, or combining features to make a program. It would seem to be that there is a need for a user to be able to do that sort of thing only, without getting into the frequency response part. Perhaps there is?
Some hearing aid apps offer a great deal of adjustment–others much less so. Resound is known to have a great app and I think Widex’s app is pretty good. Phonak and Oticon do not offer much control with their apps (but they both offer great hearing aids)