We bought the Adventure Pack for $15 each, which included 3 rides. That is the only way to go - I wouldn't pay more than $5 for each ride. The rides are VERY short, but they're really fun. We went during the day, about 1:00, and we didn't have to wait at all. The staff was courteous, and it was a clean environment. This is something we'd do again if we're in the area.
I would not recommend the zombie one for younger kids as it gets pretty intense and in your face.