Thunder Hill in Willows is the least expensive track to drive on, or take classes at. $189 for 5 20min. laps including: instructors/lunch/classroom. Fall and spring are best, otherwise it can get really hot, 100+. 2hrs north of the bay area. BTW I'm only 20 minutes from the track, and have a wide assortment of tools to fit your needs, including a lapping machine!