Even buying a Costco membership for the sole purpose of buying glasses will likely save you money vs LensCrafters or independent eyewear stores.

My dad's last two pair of glasses (reading & normal) cost him $2100. That's criminal

Yes.

https://customerservice.costco.com/app/answers/detail/a_id/8...

That said, you don't to see their optometrists, if you want a cheap prescription to go use online.