X2 on cheaper ones.
I love my Columbia polarized from Costco for $50. I have a number of even cheaper ones, $25-30. And one pair of expensive Rayban P's now used mostly for driving. The Raybans did also serve me well fishing for Bones and Permit in Belize.
99% of the time, I wear my cheaper ones though. I'm brutal, I lose them, sit on them, have them fly off my face and rattle around on the boat etc. I'm forever finding pairs of sunglasses that I thought I lost. Down behind the couch, left in looks nooks in the garage or shed, under car seats, boat seats, in tackle bags and boxes etc.
Maybe if I bought more expensive ones I would be more careful? I don't know though...and I don't want to risk it.