There are a number of newer players in the game recently, and they have noticed the difficulty of making lv2+ gems because of the cost of the potion. I would propose making the potion drop from mops. In my opinion, it is way too difficult to level gems even up to 3. Just my thoughts on the matter. For me, I have even hit a wall in leveling my own as it is too expensive to blow lv1’s from daily and lv2’s do not drop often from the daily pandora.
Just my observations.