I have seen many early N6's sell in the $4,000Cd.($3,000U.S.)price range. If you were to sell at auction, you might not even get that. If you still need a combine, why not keep them around, as you know what you have put into them. Maybe you have a neighbour who knows that they are in good and well maintained condition, and will offer you a decent price. As an example, I have seen an early R60, with a pickup header and super 8 pickup bring only $18,000 Cd.($14,000 U.S.) A lot has to do with the area your in.