There are several listed on eBuy at this moment. Look for "accessory rangefinder" under "cameras & photo." Prices look a little high to me, but I might be wrong about that.
Certo6 has a good refurbished Voightlander shoe rangefinder for sale on the 'bay. One of the few sellers you know you can trust to have a quality item.
I'm probably way behind the times with this, but for a while I seem to remember that Fotoman Camera, Ltd. was continuing to sell off remaining merchandise after they went out of business in mid-2009. At one time they were offering this small Dead Link Removed unit marked down to US$125. However, I don't know their current status, if any, except that their website is still around.