Ah, but there are more pricing models than one. Take your glasses example:
Like everything else, I buy my glasses online at places like 39dollarglasses.com (one of quite a few such firms, but I have personal experience with them) You need your standard prescription plus your Interpupillary distance (distance between eyes)
They offer PDF printouts of frames, so you can roughly see how they fit. It's not great, but then I'm not looking for top fashion.
I've had lenses that were mis-made several times, but that was done by the expensive opticians, and I've never had a problem with the online ones.
This enables me to have 4 pair of glasses for computer use and for driving, with spares, and costs less than $120 TOTAL, instead of the usual $280 per pair.
My exams are NOT free, as I see a professional optometrist, but it's paid for by my health insurance. Instead of the huge machine with the dozens of lenses in carousels where the doctor constantly asks which is better, she has a computer operated unit where I stare at an image and it somehow figures out my prescription. A couple minutes on that, another machine that puffs air at my eyeball to check for glaucoma, she does a exam of my eyes with the bright flashlight, and I'm done. She then usually spends some time discussing how much my prescription has changed, and why (because I am getting old, that's why)
Things have changed.