James, Where are you located? area can make a difference, but you do have to decide what seems right to you.
There is a 140 in the YT classifieds right now with cult and plow -- it is about $1800, and climbing. Reserve has not been met yet.
I just bought a nice 140 in S central PA for $2300, and it had a real low S/N - 554!
Good luck in your tractor hunting! Don