I was in the market for second hand kits for a while and, watching the market, determined that 20-50% loss is pretty typical for used kits. The less done the better but even untouched kits are usually sold for a loss.
Vans posted an unclaimed QB kit on here and it didn’t seem to get any special traction so I am assuming that if you did the same, you would take a loss.
If you know you’re building, get it all. If you are still deciding, order the wings ASAP and order the Fuse as soon as you start the wings. By the time you are done with the tail you will know if you want to build. The finish kit is expensive and you will take the biggest loss on it, of all the kits. Seems a kit with the finish kit doesn’t really bring a lot more than one without. And you might be able to cancel your fuse order if you have changed your mind on building.
Hope that helps.