i found a semi local business that must build crates or something for all they make
they sell the left over OSB, so i bough the biggest size they had, 4X2 at 4.40 a piece
times that by four, gets you 17.60 for the coverage of a 4x8 sheet
and added bonus, the 2x4 sections were pretty easy to lift on my own
oh, and since that roof is 10x8 i was able to buy 10 sections of 2x4 with no leftovers