Just an employee, so I have no say in selling, though we may be in the market for a flatbed in the next couple of years. Will probably always keep one JV3 around though. These things are tanks, and a joy to work on.
Sure, they can sit with solvent in them for ages, but I wouldn't do that in a cold environment, or a place with temperature fluctuations. If I had any hope of using or selling it in the future, I'd flush the lines, clean the pumps, remove the heads, flush them with solvent and store properly, throw out the dampers, and have only air in the lines before tossing it in storage.
Besides, the idea of a printer with any fluid in it, while in transit, terrifies me. We bought our second one from someone who didn't decommission it properly, so there was still ink in the lines. By the time it got to us, there was ink all the way down the legs of the bloody thing, and it made its way there through the boards.
That was a long day spent with solvent cleaner, a fan, and a giant box of q-tips.