I have two ball-screws that I saved when decommissioning a CNC grinder. I was planning to use them for my own CNC-router project but never got around to it. They both were installed about a year before the machine was decommissioned and worked fine in a precision grinding application (with 10 micron tolerances) so they both are in good shape. They are Swiss made, highest grade and cost about $3000 and $1800 each. I also have the bearings.
1. D 32x5mm L 475mm $300
2. D 50x10mm L 1100mm $700