Cycling Sunglasses

I know there are a number of cyclists on here. What are your preferences with sunglasses. It's time to upgrade from the old M-frames and I'm looking at a couple different options as of right now. I have centered most of the search on some different Oakleys, mainly the Radar line, but I have also come across some Tifosi glasses that look decent and are much cheaper. I would prefer something that I can switch from a day lense to something clear or amber relatively easy, but it's not a deal killer that they lenses are interchangable. Is it worth spend $250 plus on some of the easy switch Oakley line?