some times the best place to find a tractor is auctions, older smaller farms and estates going to auction, so family's can close things out
I seen countless tractors go real cheap at a LOT of auctions over the past few yrs< heck I even sold two of mine at them LOL(lostr my a$$ on both, due to rain and poor turn outs)
that or older tractor forums and sites
or even long time farmer CO op's and ag stores(like Agway ans such that deal with farmers all the time)