I am from cheap part of Europe. While you can get glasses for 20 Euros, with those kind of requrements 250 sounds about the same.
I guess some countries might get prescription, but I doubt “light frame and light lenses with darkening” would qualify.
If someone is being finaned by ads, they are doing something wrong. That is not sustainable nor secure, especially if one wants to reamin truthful.
Ads are used to control media, and are a bad thing. Also ads are not problem, bit random JavaScript executed on my computer is.
Put paywall (just don’t push it into my search without marking it as paywall), Patreon, sell hats and t-shirts… there are better ways.