cheap plywood?

cheap plywood?

so, this weekend we finally busted into the attic of our home. expecting a tiny, nasty little space, we discovered a HUGE unfinished area! the ceiling is kinda low but with a little work i think we could turn the attic into usable space for something besides storage. the problem is the floor. like most attics, it has a framework of boards with insulation in between. we don't need anything nice looking, basically just some plywood to lay down/nail in up there so that there is somewhat of an even surface. the main problem here is that we don't own, and we're moving next year so we don't want to spend a ton of money on plywood that will basically be useless in a year, especially since we have to cut it down to get it through the attic entrance. does anyone have any tips on sources of cheap scrap wood or how to get the best deals? we are in richmond, va if that helps :)
the beginning starts here…

the beginning starts here…

Would rather go organic.

Would rather go organic.

Ahhh!  Help!!!

Ahhh! Help!!!

Hello!

Hello!

A Work in Progress

A Work in Progress

Spring in Kent

Spring in Kent