After helping liquidate my late friends collection, you realize how much stuff you really have and what becomes of it after you are gone. It becomes someone else's problem.
I got rid of many a "rare" and "Valuable" kit that was not built and it really makes you think, Why not build them? Really, why not enjoy them instead of saving them for somoeone else, because that is where they are going to end up unless your family or friends throw them in the trash.
And if you are doing it for an investment, then you better get to moving them out as the market, i.e. buyers, are rapidly shrinking.
So, enjoy your rare kit by building them or at least think you are going to someday.