Non grommet tarps:
-Integral Designs Siltarp 2, 8 x 10, $120.
-MLD Grace, 9 x (7,5), $120.
-Oware flat tarps: 6x10, $89. 10x10, $127.
Condensation under a tarp has rarely been an issue with silnylon.
You may be able to sell the Tyvek tarps if you are 50 to 75% of the cost of a silnylon tarp (as above). Personally, any weight savings with tyvek is matched by poorer hydrostatic head.
Sun shade maybe?