What about all the costs in developing the test procedures? Obtaining the test equipment. Designing and building the test rigs. Designing, coding, and debugging the test software. Training people on how to do the tests. Endless committee meetings on if the tests are accurate and complete. Failure analysis. I bet they're enormous.
Running the same tests again on another part would be at very little incremental cost.
Much of the cost here was (on the ground) assembly and testing, given the intricate nature of the setup.