Hi Geoff.
For manual SCT Crayford focusers I recently picked up one of these from WO in Taiwan for $175 US including shipping:
http://www.williamoptics.com/wo_shop...roducts_id=148
You would need to fit it to your OTA via the original threaded visual back
I'm not sure if that offer is still available, but it was a good price. It was one of their eBay overstock specials.
One of these sold a few days ago on Astromart for $90 US.
Regards,
Eric