Hardly worth spending all that money on keys and slots. Most of the items are pretty useless and the rare ones you get anyways eventually by playing the game regularly.
Atm the Heptagonal Gems are not a must have but sooner or later they will be and by the time they are important the Octagonal Gems will be the ones where you have to spent even more money to upgrade them. All this wouldnt be a problem if Mysterious Crystals would drop in more dungeons than just Cold Storage and Radiant Energy wouldnt be so fucking rare.
The volume two book that you didn’t take that cost 20 gold. I got one of those day one of the trove for 20 but it sold for 60 gold in the market. It was my best profit yet from the trove this time.