Apple has been interested in getting into the health space. This is a perfect new product for them. The only problem I see is that the market might be too small to make a difference in their profits.
It is probably simply that it isn't so absolutely difficult for Apple to start making these. The company is already experienced in making small electronics, earbuds, and things like this.
This is what made them extremely expensive for a good part of their history. Adaptability and auto-adaptability.
Also, they're very small electronics for what they do.
I'm not seeing where "markup" is coming into this.
In the spot where a couple hundred bucks worth of services and a couple hundred bucks worth of electronics becomes $2,500.
Of course, the same as with headphones, you can spend $5K, 6K or even 10K in some top of the line planar magnetic whatever Audeze, Stax or Hifiman, but really, you don't need them.
Think also about the economy of scale. Hearing aids are more common than hi-fi high end in-ear monitors. If any big player in the electronics field enters this game, prices (and features) could be way better than they are now.