Most salvage doors are "salvage" because they were taken off a trailer with problems. If I were you, I'd be very reluctant to buy a "used door" without first inspecting it COMPLETELY before paying for it. Since the price of travel being what it is, it's probably much cheaper to pay for a new door locally than to try to find a used one, risk the possible issues with it and still have to pay exorbitant shipping charges since it's too large for UPS or FedEx.
If there's a RV salvage yard near you, maybe you could "luck out" Otherwise, I'd suggest not trying to find a $50 savings that won't work and you can't return....
That said, there is an extensive list of RV salvage yards, suppliers and manufacturers as a "sticky" as the first thread in the Repairs and Maintenance section of the forum:
https://www.keystoneforums.com/forum...ad.php?t=12986