Ultimately all products prices are explained by the law of supply and demand.
But lets dig deeper as to why. This answer is for the US only
Supply. 97% Hearing Aids are sold through 6000 to 9000 audiologists, 650 Costcos, Sams clubs and the Veterans Administration.
Think of how DeBeers used to control the flow of diamonds. When you control the flow you can control the prices.
The top 5 hearing aid manufactures; GN Resound,, Siemens, Starkey, Phonak, Oticon, control the audiologist channel - about 6000 to 9000 throughout the US and Canada - many of these offices are owned partial or outright owned by the same manufacturers. There are only 17% independent audiologists left. The Big 5 also own http://planethearing.com - where oddly enough all models seemed to be the exact same price in respective categories (don't call that price collusion). And they are all in Costco - except Starkey. Costco has reasonable prices but they are still around $2000 for a pair - and those are private labeled from GN Resound. Costco is now the largest independent seller of hearing aids in the US. SamClubs sells Liberty Hearing Aids are sold which I think is now owned by Starkey.
This is the current method of distribution. 6000 to 9000 audiologists, 650 Costcos , and Sams clubs.
Hearing Aids are not like eyeglasses. The stigma and resistance to wearing eyeglasses diminished in the 1950s and was pretty much gone by the 1970s Eye glasses were never a symbol of surrender to age or infirmity. Eyeglasses successfully moved out to the doctors office to a billion dollar eyeglass fashion retail industry -just look at the evaluations of companies like Warby Parker.
Hearing Aids are different. They ARE symbolic of surrender to age. People are resistant to even thinking about trying them. People are embarrassed by having to wear them, even now that technology has made them tiny, nearly invisible, 100% digital, with pocket remotes - thus liberating users from a device for fiddling with volume - and they have notorious reputation for not being used and being returned. If 100 people bought hearing aids, 15-20% return hearing aids. 40% will wear the all the time, 40% may wear them occasionally or have them sitting in their draw. Seen or unseen, the consumer still feels old and diminished by wearing them...or even thinking of wearing them. Consumers are not busting down the door down to buy hearing aids.
The dominoes of lower prices are starting to fall in favor of the consumer for lower prices.
Recent News out Texas, Walmart was testing selling hearing aids without licensed audiologists or dispensers, they were simply asking the customer to sign a waiver - which is the current Federal Law -21CFR801.420 . Walmart was sued by the Texas State Board of Audiologists. The State Board of Audiologists lost. The Court decided with Walmart because they found someone over 18 is able to make decisions about their own body.
The Biggest opportunity for hearing aids sale is through the internet . Why can't a consumer, with hearing loss, sit in their home, order a hearing aid from their computer, have it delivered to their house, reprogrammed at any time, to their liking?
Companies like mine, Century Hearing Aids are offering this. We purchase hearing aids from smaller hearing aid manufacturer’s like ExSilent, Audina, Persona Medical, Manan Hearing - That build quality hearing aids for a fraction of the price. They use the same chips that Starkey, Audibel and Beltone use.
The Top 5 manufacturers are private labeling their hearing aids and selling through other online stores such as audicus and embrace.