First, that's a good price. Second, why are you getting white? are you growing in summer and need to cut heat down? What will you do in winter? We need more info for a better answer...

Dan

I cannot find panels this reasonable in anything but white.......

Those just say corregated plastic. It almost implies they are poly carb because of the shipping information......but you'd better check to see if they really are. I think not, given the price. They really don't give any specs with it. Where did you find out they have 70% light transmission? They do not indicate they are UV stable. If they aren't, they'll yellow, and crack eventually.
Sooner rather than later.

Got another plan. Found 6 glass panels out of sliding doors!

Good for you!