Brian, We would retail a plow like that for around $500. If it has a John Deere Hyd Cylinder with a stop on it, they are special and would add a little to the value. Used Coulters are going for $75 each.
IMO around here plows typically go +/- ~100.00 a bottom...add for excellent condition and collectibility....subtract if its rough/needs the wear parts replaced. What you got there, I say is 100/a bottom exactly..MINUS the cylinder.
Personally I wouldnt pay for the original JD cylinder unless you plan on showing it....you can get a brand new ASAE 8" Cylinder for 50.00 all day long...
If you end up not wanting it....Disassemble it and palletize it for me. I'll buy it from you...seriously....
I wouldn't get too caught up in te price per bottom, as the condition of the unit can vary quite a lot. The Deere cylinder with adjustable depth stop is a good quality unit and is far better than the run of the mill $50 dollar ones. These things were costly when new but are great for their intended purpose on a wheeled disk or plow. I had one on my Amco offset disk many years ago.
I called a few minutes ago to tell him I would take it for the price we agreed upon earlier and he told me another guy just gave him a down payment. Thanks for the help guys! I will have to keep looking.