I'm not going to disclose where I buy my glasses but when I bought it locally, I could very easily spend above 300€ for stock lenses and a basic frame.
I needed a lense change every two, at best, three years. Between wear and prescription change, it was necessary.
One year I spend nearly 400€ on prescription glasses. Under less than 3 months I have a lense peeling, the coating flaking off the surface. I file a complaint and the lense is sent to the manufacturer for evaluation abd it is found I am to blame. No exchange, no refund.
I decide to take a gamble, go to an Ophthalmologist, get a medical prescription issued, and then have my glasses executed externally. All things added, I spent 130€ to replace my glasses.
The next time I go see the same doctor for a checkup, I get complimented on the quality of the lenses I have but criticized for overkill (very low thickness, which I really don't require, anti reflex, UV, scratch resistant, etc).
I have never bought glasses again in my local market.