If you can get it cheap enough then it still may be worth getting but really an inspection would be the only way to know. Chances are if the lube system was working then the screws will be ok and likely just the thrust bearings are needing replaced. Inspect the screws and see if they are pitted or look badly worn, if you can remove the motor and turn the screws by hand to see if they feel rough. If the screws are a bit worn it still may not be all bad as you can get them cleaned and reballed, the larger balls run on a different part of the ball track so should be on an unworn part. Having said that it all depends on the condition of the screws, if they are badly rusted then it may be even reballing will be no use. Inspection is the only way to know for sure and getting at a cheap price (scrap value) is a must I would say.
Hood