How bad are cheap sunglasses?

I’ve been looking for a good pair of nice sunglasses. $100+ range. However much to my dismay I’ve not been able to find a pair that looks good on me. I have on the other hand been able to find some nice ones in the $10-$30 range. So my question is, just how bad are the cheap ones? Are the expensive ones really worth it?

Cecil’s answers the question:Do old or cheap sunglasses increase the risk of eye damage from ultraviolet rays?

“Assuming you don’t want to spend two grand for gold frames a la Stevie Wonder, you can get shades that effectively block UV for maybe ten to forty bucks.”