Earlier quoted context omitted.
At least in the US that would be much cheaper: I can get high index (1.74) lenses for +$75: https://www.zennioptical.com/glasses-lenses (so the overall glasses are ~$100)
I have a Zenni pair, I think they are 1.74 and around -6 correction in each eye. They are really cheap compared to other places, but they have very high chromatic aberration on the sides and I don't thing they are perfectly centered. I think it's something that's more noticeable when you need relatively high power lenses.
It's nice being able to grab a cheap pair of glasses for activities where there is a high probability of them getting damaged or lost, and having a backup pair handy. The reduced mental load of not having to worry is worth it!