Red Heart 4ply yarn for a major project.

I am almost out of donations. I need red heart 4 ply yarn because I am making 202 cat blankets to be divided between the Berkshire Humane Society and the Eleanor-Sonsini Animal shelter. The blankets measure 2 1/2 ft. by 2 ft.
I just started blanket number 113. Wall mart was my supplyer until they sold it all for a bigger food section their store. Right now instead of paying $2- for a roll of yarn other stores are charging at least $3- and I still hav 87 more to go.PLEASE HELP ME.