New Holland 850 value

Many many Farmers around here are still using the chain balers, Hence the higher prices. But in my opinion if you are going to roll with a old baler might as well use one that you know for sure will roll. A NH850 will roll when you need to roll.
almost Lost some hay last year to a belt baler that wouldnt roll the hay when it got too dry. Had to break out the square baler and bale way more squares than I was ready or had help to do to beat the rain.

I have a NH chain baler like that one. Not only should you pay attention to the chains - big apron chain and floor chains, but also check to make sure that the floor is not all rusted out. You can get new sheet metal for it, but it is a pain to work on.
I have a diesel Ford 5000 that I use on mine. It works fine, but it does snort once the bale is just about done. Snorts even more when full and going up a hill. It is kind of nice, cuz you can judge how full it is just by the sound of the engine.
The bales are not real tight and look kinda sloppy, but you really have to be trying to plug that thing up. It will eat anything including cornstalks.
I wouldn't pay much more than $500 -$700 for it unless everything else is in real good condition. You will probably put a minimum of $200 into it just to get it going.
Good luck.