There doesn’t sound like there as any "exact equivalents" in any business. It is all a guess, and it needs to be an educated guess, do what you are doing and keep asking questions (I like some of the replies) and also educate yourself as much as possible, do a butt load of research, know all aspects of the business, prepare for the worst, not sure but I’m thinking a lawyer and accountant for my truck when I finish doing all the above!