Office overhead is just due to the monopolistic reliance on a few expensive aids. Optometry requires specialists of differing degree (optometrist vs. opthamologist) yet contacts are dirt cheap because of industry competition. The same is true of corrective glasses, LASIK etc. etc. Hearing aids shouldn't be any different.
My wife is Korean and was shocked that she couldn't get a pair for like $30. Also, I think the glasses she ended up with were probably considerably more than $100 but your options are really narrowed if you have an Asian nose (many glasses that would work fine for me just slide off of her face).
I am currently wearing my "looking at the monitor glasses" that I bought from Zenni Optical.I bought it somewhere between 4 and 6 years ago for around $15.
I have three pairs of driving glasses, a pair for running,a rimless pair, and a pair for use at work. They are all from Zenni and were all bought 4 to 6 years ago. They have various levels of tinting from none to fairly dark. Antireflection and antiscratch coating were standard. The most expensive was $30.
I would like to buy some new glasses from Zenni, but my optometric prescription has not changed and the frames and lenses are still in ridiculously good shape.
I rejoiced when my work glasses has a nasal bridge fall off. Unfortunately, I found that I was able to repair it in a few seconds.
So despite the pittance that it costs, I still use these old glasses. Perhaps if I carefully drop some dumbbells on them.... :-)
I paid $30 for a pair of glasses from Zenniopitcal and they are of fine quality, not dissimilar than the $300 I used to pay. My girlfriend has been using them for a decade now and she's asian...