The Encyclopedia Britannica is to cease publication of a printed edition after 244 years and go digital only. In 1979 my parents bought for me a set of the books assured by the salesman (who gave us a nice slideshow) that it would be a worthwhile investment both in me and financially as the books would never lose their value. They were not cheap though i was too young to understand such things at the time but it must have cost my parents a sizeable chunk of their salaries to get it for me (we've never been a rich family).
But it has kept its value of course... or has it? Actually no. One of my volumes did have some minor printing errors (a few pages getting mangled) which was not noticed by anyone for years so a few years ago i had a look on Ebay to see how much it would cost to get that volume again. To my shock the entire set of volumes (the same edition and bounding i had) was on sale for... £60! It would have cost my parents the equivalent of a few £1000s back in the late 70s and early 80s so one cannot say its kept its value.
Still it looks good on the shelves... though i am running out of shelf space. I won't get rid of it though, it was the gift of knowledge even if i never used it and sought my knowledge elsewhere myself.