Saiga in 5.56 or 5.45: $300 - $400. It's easier to load and operate than an SKS and will have less recoil.
Great idea!
Since he said he thought the Wasr may be a little too much recoil I was going to add to my suggestion an AK74. I forgot about the Saiga in 5.45
Should be fairly easy to find in the $350 -$400 range and cheap ammo.