OP here. The lowest I'd pay for glasses if I bought them at my optometrist would be $500. My insurance covers $300. I bought one pair from Clearly Contacts for $199 and one backup pair from Zenni Optical for $79.
I took them both to my optician today. They didn't charge me, I offered to pay. The result?
The more expensive glasses had the wrong pupillary distance and wrong astigmatism correction on one lens. The cheap glasses were perfect.
Granted, Clearly Contacts is replacing them, but it's disappointing.