Low Level Quality and Appraisal Prevention Cost, Internal Failure, External and Oe. If inspections decrease, external/internal failure costs increase. Ob. Quality is not costly in both directions, either high or low. Oa. If inspections increase, external/internal failure costs decrease. Od. Total cost of quality is the sum of external/internal failure costs and prevention/appraisal costs. High Level Quality of Quality Total Cost. Which one of the below statements is not correct based on the cost graph below?