Where can I get a cheap copy of Rage by Stephen King ?

Your local library

Apparently it's become somewhat collectible, both as one of the novels and novellas in "The Bachman Books" and when published by itself earlier, both under the pen name Richard Bachman.

I saw a used copy of The Bachman Books at Amazon for under $17, but that's not cheap.

It's entirely possible your library owns it, if you're in the US. I just took a look at my library's website and they have The Bachman Books. Good enough if what you want is to read it rather than own in.

From anyone, really. Simply walk through the streets of any major town or city and stop & search random passers-by. Go through their bags and pockets and you never know...... one of them's bound to have a copy at some point. If anyone objects try slugging them with a lead pipe, or something. That's how I got my copy of "The Shining". Hope this helped, y' anon twit.