I am just glad that they were not Berserk books. Manga (Or at least Berserk because Berserk is only manga I bought) is more expensive than most normal books so I would have been even more frustrated. But yes, I found them eventually.
From what I remember my dad had a small(metal?) box with coins. I looked for it multiple times but was not able to find it. Shame, maybe it could be worth something now... My dad also collected postage stamps. We sold few albums and got 150(?) for it. We still have some albums. 150 is much less than I expected but it still is something.