Revenue and Gross Profit. First, consider the meaning behind the revenue and gross profit numbers on your income statement. Revenue equals all the income generated by sales of products or services during a period. It includes both cash purchases and purchases on account if you use the accrual accounting system and record revenue when it is earned.
A clutch job, (new pressure plate, new clutch disc, new throw out bearing, and new pilot bearing) apparently costs somewhere between $500-$600. Replacement OEM parts cost about $170. (links off of Miata.net will get you a number of good suppliers). So if you do it yourself, you might save $300+.
The most common major transmission repair is a clutch replacement. Three parts are usually replaced during this repair, the pressure plate, clutch disc and throw out bearing. The pressure plate costs between $40 for a four cylinder economy car and $150 for a high performance eight cylinder. Clutch discs cost between $30 and $200, again with the high number being for a high performance vehicle. Throw out bearings cost between $20 and $50, depending on the application. Many parts stores carry matched set clutch repair kits. These cost between $100 and $800, again depending on the application and manufacturer. Other parts that are replaced often are the clutch cylinders, both master and slave.