opticsplanet has decent prices on real ESS glasses:
http://www.opticsplanet.com/s/ESS+ICE/
I just ordered a set from them... there are 5% and 10% discount codes floating around.
but if you're playing at paintball fields, I'd highly recommend JT Flex 8's. You can run the full mask (e.g. when playing CQB) or detach and just run the goggles. The lenses are thermal to reduce fogging.
http://www.paintballgear.ca/product/...Sand_Camo.html