$64.99 STandard 3/4 4x8 sanded plywood from Menards for $40, 1/2 is $30 - http://www.menards.com/main 
ReliaBilt 1/2-in x 4-ft x 8-ft Maple Sanded Plywood in the Plywood department at Lowes.com
1/2 in. x 4 ft. x 8 ft. ACX Treated Sanded Plywood | City Mill
