Just make a will, but don't inform anyone of the value of anything outside of the will, ever. It is no ones business what your stuff is worth in advance. All it will do is generate issues right after you die, if not prior in your marriage and with your rebellious problem teenagers looking to score quick cash, let alone with family members bickering amongst themselves on who gets what with cash signs in their eyes after you die.
And also, state in the will that anything game related will need to be properly re-evaluated for current market values by a professional, since going rates can change from year to year. State also to be sold by a professional with references and experience in game sales, with the money from the sales going to whomever it is you choose in the will.