I made a simple little Manufacturing Calculator for myself and decided to share it with anyone who wants to use it. Its not as fancy as some, but it can factor in different expenses and you can enter whatever price you intend to pay for materials and the price you payed for the blueprints. Or you can only factor in your income and leave out the expenses. Plus if you want to keep some of the items you manufacture, it can account for that too. OH! and you can use it on the In Game Browser, which is nicer than using excel... just make sure your Browser window isn't too small or else the form will look weird. So here is the link if anyone wants to use it: EVEulator
hope its helpful.