I ran "Sinister Secret of Saltmarsh" from Ghosts of Saltmarsh this weekend. My players and I loved it. (It was one of my favorites when it was first published.) Don't read ahead if you don't want to know about a particular treasure, though I'm not giving anything away other than to describe it.
While browsing ahead I was struck by the solid gold apple that is valued at 5 gp. Say what? My back of the envelope calculations suggest that a small apple would require about six pounds of gold. Wouldn't that be around 300 gp for materials alone? The values of it and the other objects in that locations seemed bizarrely low. I'd imagine that a skillfully carved wooden apple might be worth 5 gp!