The way people typically do it is charge by value of project -- "this component is worth X dollars". Businesses want to solve problems costing D-dollars in T-t

The way people typically do it is charge by value of project -- "this component is worth X dollars". Businesses want to solve problems costing D-dollars in T-time for themselves. They couldn't care less if you spent 1 vs 10 hours on it if they can't do it themselves, so why bother oversharing your time expenditure?