I bought glasses out of insurance from a company that I don’t think sells out of insurance glasses anymore. But it cost like $120 (getting glasses the normal way would’ve probably been a 4 digit number, so I consider $120 cheap for glassss), all I had to do was find my old prescription numbers then increase them by like 1 increment. Saved tons of money. Your eye doctor will refuse to tell you your prescription numbers if it’s been more than 1 year since your last appointment but there are ways to measure the lens curvature using light and shadows. You can’t get them any cheaper without becoming a glass blowing expert and doing it yourself, and you’d have to diy a lot of other far fetched stuff while you’re at it, so good luck with that