Don't look at me to talk you out of it. You have a higher and stable milk price, and potentially unreliable and costly help, and plenty of years ahead of you to amortize the investment in.

Let me know when you have them in, I want a farm tour(smiley face).

I would have to buy used ones awful cheap to put up with the aggravation that will come with moving-picture your service guy making a funny face as he says, "Ive never seen one quite like that before". IMO, something like this, that has to work properly, 24/7/365, is something that should be purchased new from the source of service. With the rate of evolution in electronics, buying 1 or 2 year old stuff is like buying week-old bread-it might look the same, but......