I tried going the cheapo sunglasses route (MEC FTW!) but then one day i was dumb enough to step into the oakely store to see what the hubub was about and $300 later i walked out with a pair of Split Jackets *sigh picked the fire iridium lenses for daytime and yellow for dimmer, overcast days.
that said i've never looked back. vented lenses are top notch - never fog up when i'm riding. they do when i stop but it goes away as soon as i start moving again. for the overall comfort, durability, ability to change lenses, and craftsmanship i'd say it was money well spent
amazing how much 'technology' goes into these things. oh and they look sick too