If the parts are still in the home just in a different kit box or on a different model it shouldn't affect the price at all. All of the kit parts are still in the house, it doesn't matter which box or kit they are on. If, God forbid, a fire happens and destroys your collection you are, for example, still going to have to buy that Corvette kit to get the motor and wheels you put on that Nova kit. Also I would quote even the open kits at $20 - $25 as you are looking at replacement cost in the event of a loss, not what you could sell them for. I've had this conversation with my insurance agent and that was the advice I got on assessing a value to my collection.