I had a pair of Fossil sunglasses for a day I ended up returning them. The optics on them sucked, and were driving my eyes nuts (I had picked them on on a whim without really paying attention to the quality), . I was used to wearing prescription sunglasses for so long (got LASIK last year), and I always paid to get the best lenses I could get, polarized, quality prescription lenses. So when I wore the Fossil's I noticed the bad optics. I then got Bolle's which worked great for me, and the difference was apparent compared to Fossil's.
I've heard great things about the Maui Jim's, and I thought they were great when I tried them on today, but the styles they had in store sucked. I liked these Ray Ban's and after wearing them, the quality felt a;most as good as the Maui Jims to me so I picked them up.
So I guess it's up to you if they are worth it. To me, quality lenses are worth it. But then again, I was used to paying $300-350 for a pair of good quality prescription sunglasses. From wearing glasses for so many years, I'm used to being very careful with my eyewear. I don't break them, I don't lose them, and I try to keep them in great shape. If you are the type that loses or breaks sunglasses, pricey stuff like Maui Jim's, Revo, etc probably aren't for you.
Buying them at Costco helps to take the burn off a bit though, the prices on the Maui Jim's was excellent there. Most of the pairs they had were in the $95 to $110 range, but the styles they had didn't appeal to me. I just liked the style of the Ray Ban's better, thought the optics were just as good to me, and the price was great.