I don't have a way to get Crystal Energy with cash. I'm unsure if I'll use Crowns to buy CE in the Market for the purpose of crafting and upgrading equipment since there's always the Auction House. Is grinding for Cr, hunting for materials and buying the recipe good as opposed to just getting the Cr and getting them from the Auction House?
Another question, can players use Mist Energy instead of Crystal Energy for crafting? (i.e. Recipes that require 50 Energy to create, such as the Autogun, and using all your reserve ME before eating up your CE for 100 Energy and above recipes)
I think so. It can set you back thousands of Cr's when you craft equipments instead of purchasing them from AH or any other shops. It takes patience, but in the end it's worth it.
And yes, ME's are always used first for crafting. CE's are used only when you've run out of ME.
CMIIW.