I've never been a fan of expensive sunglasses.  And I've even tried the "higher-end" cheap ones, but I've never had any that feel good and don't make me look like an insect.  So I buy $5 plastic sunglasses at Walmart.  But the problem with $5 plastic sunglasses from Walmart is that they routinely shatter right as I'm putting them on my face, usually after about six months of use.  So then I go back to Walmart, select the cheapest sunglasses that don't make me look like an insect, and repeat the process.  I've probably gone through about a dozen pairs of sunglasses in recent years, so it's really become more of a sunglasses tax than an expense.