Is there a "kellys Blue Book" for Tillers and tractors? Is there somewhere to research or a reference that will tell you about performance? How well they

None that I know of but when buying a used machine it sure helps to know the price of a new one. This might help you Used lawn mowers markets guide (http://www.lawn-mowers-and-garden-tractors.com/used-lawn-mowers.html)

Thanks ballengerb1