Grizzly sells a high-quality 7x12 for $649 shipped, with a one year warranty. (Grizzly ships warranty parts quickly): http://www.grizzly.com/products/g8688
and it includes several accessories that do NOT come with HF or MM version.
THIS may be one of the first available Sieg 7x12s with BLDC motor:
These are all quintessential mini-lathes, with 3/4 inch spindle bore. They are all light weight (90 LB) enough for one person to easily move around.
NONE of the foregoing lathes are recommended for turning ball screws. Hardened ball screws are very difficult to turn in a mini.
There ARE ways around it though.
1) You can use a grinder attachment to take off the hardened outer layer--and finish on mini. Cost about $200.
2) You can anneal the ends of ball screw, which, once softened, can then be machined.
3) You can drill the ends of the ball screw and fit extension shafts to ends. These softer metals can then be turned.