Good idea to sell the pallets!
What you have to watch with coops from pallets is that red mite love all the nooks and crannys' that appear when using pallets. You would need to creosote the inside and probably line the inside with plywood (stained too) to prevent infestation.
I made a run for the chooks with pallets, now that makes more sense. Sure is a pain in the *rse getting the pallets apart though.
Ian