Hi Boyd
Have you thought about going to your local High School?
Most high schools have lathes and machinery that are more than capable of machining your ballscrews.
$1000 bucks seems a bit steep. I machined the ends of mine at school. I didn't thread them though I machined them for bearings and taped the end to bolt it to my end plates. You only require one fixed end the other can be floating.
I found the hardest bit was removing the hardened surface which I was able to do with a tool post grinder on the lathe. Once your through that you can just machine it to size as though it were mild steel.
Hope this helps.
regards
John