How does testing has a quantifiable return on investment (ROI)?

Good Testing Saves

 Reputation, did you ever calculated the cost of lost customers or negative news?

Money, a defect founds early in the process cost less than during User Acceptance Test (or when you are live).

Your project, a clear understanding on the risk makes it possible to mitigate these risks.

Any delay in a project can harm the next project on the line also and even with all extra knowledge on quality each following project goes better.