I called my local Lowes in Paducah Kentucky, and they can order 2" 4x8 sheets of 703 for $25 ea. Great price.
1" was only $12.50, but they said it was a "tongue and groove" kinda edge. The 2" would be better anyway.
I'd think any Lowes could do the same.
I called my local lowes and they didnt have a clue what I was talking about. Can you get us an item #??