For a dealer to take a trade-in and resell it later, with any kind of support or warranty, they usually would replace several parts that can run in the thousands.
I know if I were to even consider taking one in as a trade-in for resale, I would plan to replace both heads, captops, dampers, scan motor, linear scale and guides... and this is without even seeing the unit yet.
Add the Roland warranty for another grand or two... resale price on a unit that was given a $6k trade-in value would probably sell for $10-$11k... Buy a new one for $12.5k
Printer Trade-ins usually turn out to be major hassles for dealers with even lower margins than new units. Risky.