lawn tractors and ridding mowers can have value, there are features some mowers have that certain groups look for. They may be collectors, racers or have parts that work well for other projects or as parts for yard/maintenance companies. However it is very region and model specific. The only shure bet is a running diesel motor and useable john Deere diesel lawn mowers. Other than that google and a call to a small engine place are your best bet for info.