It's really hard to judge the worth of such a class without knowing class size, format, experience (including training/teaching) of the instructor. If Park tools is officially lending their name, format and syllabus or training materials I would tend to give it a bit more value. For that price I would expect a primary trainer and another mechanic as an assistant, and no more than 6 students. I doubt that many shops could physically handle more than that. That would mean $150 per hour for the instructors and overhead, which I think is reasonable. If it's one instructor and any more than 4 students I would hesitate. You will be getting a "minor" tune-up in addition to the knowledge, but I am concerned that there is no mention of even minor wheel truing.