I'll try to explain this so you understand and don't have to ask next time =p Assuming you will be buying pure essence (rather than mining it), let's call the number of pure essence you will buy '#Pess'. The number of cosmics you will therefore craft can be written as '2*#Pess' (since it will be double the amount of pure essence you will buy). Profit can be written as = [outcome $] - [used $]. Since $ equals (value)*(number) So, Profit = [(161)*(2*#Pess)] - [(150)*(#Pess)] Setting Profit = 10m, we get: 10,000,000 = [322*#Pess] - [150*#Pess] = 172*#Pess So, #Pess = 10,000,000 / 172 = 58,140 (rounded up). This means you will have to buy 58,140 pure essence which is equivalent to crafting 116,279 cosmic runes (to answer your question). Hope that helps...