You get good deals at farm auctions when you are looking for something that doesn't match. For example, go to a construction auction where most everything is construction equipment, and there is one farm-related field cultivator. Won't be many farm folks there, so that field cultivator will go cheap, and no one will bid it up 'for fun' if it does.
So, you have to find an auction with that one item you want, but not many other items a guy like you would want. You need to be the odd-ball person at an estate sale. Consignment sales are generally 'rigged' (legally, but more 'no sales' than sales at the one's I attend) in some way to bring the regular asking price - waste of time to expect to find a deal at a consignment sale.
Right now, machinery that is in demand is for very large farms to some extent, or machinery for a 5-20 acre plot. You just won't find any deals - now. If you are farming 200 - 500 acres, there are lots of cheap deals. But then, no one can afford to make anything on that size farm, so no one is buying....
--->Paul