Instead of doing Shadow Lairs everyday or when you get the chance to repetitively, why not add 3 more lairs if not 2 to the clockworks (based on new depth levels, better gear enhancement system, and difficulty rate).
Crystal Lair (my idea)
Radiant Lair (my idea)
Cosmos (my idea)
Shadow Lair - You get enough money, more heating crystals, and unique materials - 1,800 CE (for a key + 3 depths)
Crystal Lair - You get more money than enough, heating crystals, and unique materials - 3,600 CE (for a key + 4 depths)