One race and a license might set you back about $40, but if you go with a competitive group and commit to doing 2 races, it's worth it! Just keep in mind you can only stay out there as long as the fastest car completes his laps. So if you've got a super fast racer out there with you, you won't be on the track for long.
Also, they forbid cameras! I tried to bring in my helmet mounted GoPro camera, but they told me to leave it outside.
There is a cafe inside with beers and food, but you won't be able to enjoy a drink until after your races are over.