Good point, Micah. I guess I view the TB/WP as "tinkering" with the car but that somewhat trivializes the job. It does go beyond a standard tinker which is probably an oil change or serp belt change. Now, walts car, being a 93, would not be destroyed if he did something wrong with the timing. Yours, however, being a 99, might sustain some damage.
On the flip side, doing your own work is a tremendous "confidence booster". It will boost your self-confidence in that what you set out to accomplish, with due diligence and attention to detail, you can successully complete. My son and I just got done replacing a head gasket, timing belt and water pump on a 92 ES300. I had never removed the heads on an side-mounted overhead cam engine before and he had only changed oil in a car. But I looked upon the job as a tremendous learning experience and confidence booster for him as a young man. I taught him how to research the project, how to bag the bolts, label connectors, vacuum lines and take lots of pictures. He performed the brunt of the work under my supervision. When he got stuck or discouraged, I came alongside and helped. The job is completed now and he has a beautifully running ES300 to drive around. For me, mission accomplished. No, not the head gasket, TB/WP. The mission of instilling greater confidence in a young man. And that it did. He is now "unafraid" to rip into it. The confidence then spills over into other areas of his life. The monetary savings ain't too bad either! ;)