Yup, I actually did this same thing this weekend! It was a little over $10 a sheet (not $5 as you say), but that's nothing compared to OfficeMax quoting me $16

Yup, I actually did this same thing this weekend! It was a little over $10 a sheet (not $5 as you say), but that's nothing compared to OfficeMax quoting me $163 for a 4x6 foot (framed) whiteboard. $13.04 for a 4x8 sheet at Lowes: <a href="http://www.lowes.com/pd_16605-46498-300_0__?productId=3015239&Ntt=dpi&pl=1&currentURL=%2Fpl__0__s%3FNtt%3Ddpi>DPI http://www.lowes.com/pd_16605-46498-300_0__?productId=301523... 1/8"D x 4'W x 8'H Trifty White Hardboard Wall Panel, Item #: 16605</a> Or, they also stock a 32"x48" piece ( <a href="http://www.lowes.com/pd_61082-46498-31023248_0__?productId=3042205&Ntt=tileboard&pl=1&currentURL=%2Fpl__0__s%3FNtt%3Dtileboard>Item http://www.lowes.com/pd_61082-46498-31023248_0__?productId=3... #: 61082</a> ) if you just want one for a cube wall. Note that this won't be magnetic. The OfficeMax representative said that the magnetic variety was around 3x as expensive as the non-magnetic. Comparing $13.04 to $489, I think I can make that sacrifice. I'm cheap, but I secured mine to every other stud (32") with some polebarn screws I had on hand (nice white hex head, rubber washer to avoid crushing the hardboard). That way, I just have to spackle and repaint 8 little holes, instead of re-doing the drywall. Cheaper in the long run! Oh, and it works great as a whiteboard.