The hearing aid industry is built on salespeople who get a significant commission. Add in high marketing costs and you get an $8K hearing aid. Same with home security, heat detectors, etc.
The way people buy has changed over the past 50 years. There used to be an army of door-to-door salespeople. Slowly that has eroded and then fell off the cliff with the internet and warehouse discount stores. Nowadays companies are selling direct to consumer eliminating high commissions, keystoning by retailers, etc. and that is giving the end user a much lower price.
The big threat to businesses these days is Amazon. Not only for online CPG purchased by consumers but also for brick-and-mortars; Imagine passing up a 7-11 convenience store because you have a Prime membership at the Amazon store down the block; Grocery stores are already in Amazon's sights. Amazon will even crush the insurance industry. Amazon is re-training Americans how to buy.