RE: .22 rifle
How old/big is the boy? If you are looking at youth models you may find some single shots by Rossi or H&R/NEF that fall in that range. Or I think the little Crickets are under 100 bucks. You may find some other single shot bolt actions that cheap as well.
Or like said check out the used racks, nothing wrong with them.
I had a savage youth model bolt action for a while that was pretty nice. I think it ran me around $130 or so without a scope.
Under $100 may take some looking, but add another 50 bucks to that and I think you should be able find something pretty decent.
Paul