Palace in the Clouds
Who are these stupid miners that sells unopened spirit rocks to shops? With a little effort you can open your own ores and theres a chance you get the crystals yourself. Are they slaves with no choices ? Massive logic hole in how this rock gambling tropes works. The shop keepers are also fools, sell unopened ores to gamblers for 15$ and 1 or 2 lucky gamblers will open a crystal worth thousands. Why not just have all the slaves mine and open the ores, all crystals will belong to you, just cut out the gambling crap it's uneccessary to the business.