Flat Pricing vs. Hourly (Time and Material)
When I was in business, I tried both methods. When you charge by-the-hour, something happens to a customer. They become human time-clocks. They pus for more work per hour. If I needed to go to a supply house to pick up a special part, I was always asked if I was "on the clock" while I was gone— I hated it. I was always cutting prices to satisfy customers. I quickly made the shift to flatpricing and still believe that it is the only way to go for a new start-up company, and that's what large companies are doing now. I was making twice the money in the same amount of time. Why? I simply quoted a firm price for services. It didn't matter to the customer if the job took me one day or all week. If I had to go to the supply-house for parts, nobody cared—it was my expense, not the customer's. My customers loved the arrangement. They didn't worry about extra charges when I presented a bill, the price was locked in. Before you leap into flatrate pricing, a word of caution seems appropriate. Before you can flat-price you need to have a few things.

• First — you need the expertise to accurately diagnose what the problem is, the extent of the work needed and have the ability to envision worst case scenarios— Murphy's law. It may be necessary to invest in equipment that gives you that ability.
  
• Second — organization and efficiency become increasingly important. You can't waste time chasing parts on every call. Stock your trucks appropriately.
  
• Third — test your work, leave nothing to chance. Having to go back on a call is self-defeating and loses customers' faith in your skills. Call-backs are a killer. Take your time and get it right the first time.
  
• Last, but not least — if you simply can't determine the full extent of the work needed, say so. Quote a price that allows you to do enough work to get to the source of the problem. You can then quote a price for any work that needs to be done to complete the project. I have sold literally millions of dollars of repair-work this way. Incremental flatpricing is common in our industry.