At one time I had made provision in my will for my technical book collection to go to a large organisation related to our hobby. As I found great difficulty accessing any books that they already held, it seemed that my bequest would rather wasted, so I decided to change my will.
What I need to do is pencil on the covers the current market value with the date so that when the collection in parts is sold to book dealers a fairish price is offered. Books bought 30 years ago for 30p might now be worth £30. It's just I know the first thing a book dealer does when considering a purchase is to see what I paid for it. What I paid for it & when should surely have no bearing on today's value!