50 amp extension cords

I just purchased a 1993 Gulfstream Tourmaster 39 ft rig. One of the things I am looking for is a 50 amp extra cable - just in case. Found new ones for around $200 but would rather believe that there are some used and well cared for ones out there for a lot less. Anyone know of a source for them. Bill
50 amp extension cords

Camper's Choice has a 30' for under $150 including shipping. The one I got from them works just fine-made in China of course. A real handy thing to have.