value and info on maxtron450

I have a chance to get a couple of miller maxtron 450 cc/cv welders , i am not yet sure of the year made as they are n.o.s. from a closed out welding supply house , wont get to lay my hands on them until wednesday , but would like to know what the ball park is , i have seen a couple on ebay for 250.00 but they were rode hard and put up broke