Income Tax is A COST, they just don't pay it immidiately, but they do factor it into their prices. Ask a business owner, they will back my up.
Profit is a residual which may result if revenues exceed costs of production. It cannot be accurately predicted and may not exist at all depending upon market prediction accuracy. Thus, there is no way to know how much one would budget for potential income taxes.
One just hopes they will have to pay some since that means they were profitable. Business owners never know what those profits are going to be until the books are balanced at the end of the year.