A revolutionary idea: Allow level-specific crown gear (such as professor garments found in the Professor pack) to be upgraded to the next level for a crown fee.
I first saw this idea from Cassie Dragonheart, and I wanted to expand why it would be beneficial both to the player and KI.
One of the biggest reservations wizards have about going after this gear, even when it's great gear, is they will grow out of it too quickly for the endeavor to be worth the crowns. I've personally played the waiting game on this before, telling myself "I'll wait until I reach level 50," only to find I keep procrastinating because I know how quickly the gear will be relatively useless.
Thus, allowing this feature would increase both initial sales of packs and provide additional revenue from people upgrading their gear. I would suggest an accumulating fee schedule of 50 or 100 crowns per upgrade. Thus, the first time you upgrade a piece of gear is 50 or 100 crowns, the second is 100 or 200 crowns, and so on.