Upload & Sell: Off
I don't think the differential will be that much. Direct sun is "Sunny 16" and the flip side, open shade, is "Shady 5.6" a three stop difference. So worst case I'd gues you'd get 2-3 stops less light than the direct sun.
You might want to look for one on Craigs List or FleaBay to get the frame, then create your own tent out of thinner, more translucent rip-stop sail cloth.