The problem with the rising crown prices is that because of horrible game balance there's only a few recipes worth learning and as a result crowns are inflating faster than they should.
Since I'm not optimistic about "balancing" actually ending up in things being level (and the fact that nerfing things never actually address core problems with equipment shortcomings) I suggest alchemy costs should be spent with crowns only. Having a CE cost, especially one beyond the mist energy capacity, undermines the idea of a sink of a theoretically unlimited currency (Crowns) as opposed to a limited by cashflow one (energy.)
1*: 500Crowns
2*: 2500Crowns
3*: 5000Crowns
4*: 10000Crowns
5*: 20000Crowns
The prices of crowns are not inflated the demand for them are just low. Before the prices for 100 ce was low because it was not meet at an actual equilibrium price only due to the fact high ce in the market low amount of crowns in the market. Now there is more crowns in the market and still or close to most likely same amount of Ce in the market, but as the need of Ce rises and the need of Crowns fall the price will easily reach the equilibrium price which will make it fair for both the buyers and sellers of Ce.