There IS a chance that you can find one in a junkyard. I've seen it happen exactly... once. That was where I found mine - a junkyard in Pasadena, Texas. Guess I got there right after the car was dropped off at the Pick-n-Pull yard, 'cause I got the dealer-option CRX armrest (in black) for all of TWO DOLLARS.

It needed a bit of TLC for the upholstered top, but the rest is all there, and it's in good working order. I'm redoing the cushion with a swatch of material I cut out of a '90-'91 Si seat (with the red stitching in it, so it will match my current seats). Don't worry - I didn't trash any good seats to get the material; I found a section just big enough for my needs on a seat that was otherwise a goner.
One of these days I'll get off my lazy butt and finish the top so I can install it and take pics...
Mike