I had my KDW's drop-shipped to a local shop that was on TireRack's list and they charged $12.50 per tire. So, it comes to about $53.50 or thereabouts to mount and balance a set of 4 tires, including the tax.
This amount doesn't take into account any disposal fee for old tires, as there were unworn snow tires mounted on the car when I purchased it.