Cheapest for me, would be a 1950s Smith Corona Clipper. My wife's grandmother gave it to me. I have since passed it on to a fellow typewriter enthusiast in Milwaukee.As for one I actually bought, it was a 1950s Smith Corona Silent I found at a flea market. I paid $4.87 or so. It was beat up a bit and several of the typebars were bend and disconnected from the bottom. I fixed it up, cleaned it up and its a really nice typer that I use on a semi-regular basis.