I wore out a pair of Costas, before Costas became cool. I then wore out another pair. I decided not to buy them again for 2 reasons. First, I didn't want to wear the same sunglasses that 90% of the high school boys wore, and 2nd, they cost too much.

I did a lot of reading and settled on Typhoons. I'd say the lenses are comparable to Costas non 580 lenses. That's good enough for me and they cost about 1/4 to 1/3 what Costas cost when I bought them.

If you aren't buying glasses to get a certain name on them, they are sure worth a look.

http://typhoonoptics.com/typhoon/

If my people, who are called by my name, will humble themselves and pray and seek my face and turn from their wicked ways, then will I hear from heaven and will forgive their sin and will heal their land. 2 Chronicles 7:14