I returned this year after 4 year break. I had 10 Essences of Halloween in my bank and 1 mystic chest. I said to craft them all and the open but since years pasts I thought to check cost/winning rate (after crafting 1).
If I calculate everything correct, you need ~164g to craft 10 MC and to make profit you Need to get the Essence of Lion's Arch (0.01 chance).
Any other drop you don't even get close to make even with your cost. That's 99,99% for big losses at least (not to say huge).
So maybe to review it? Either make it MUCH cheaper to craft or change the standard drops and quantity of items and the drop chance of essences?
Unless I calculate them wrong!