Um well so DH and I both do crossfit. we love it. I am not sure it is correlated to spending less time at the gym. It is something we can do together which is nice. Ok I re-read. Most people aren't going to spend more than 1.5 hours at the gym. Crossfit class is an hour including warm up (some people might go in 10-15 mins before class starts and warm up one more). He might spend another 15 mins after class working on some weakness but that is about it. It is likely to be MORE intense than what he is doing at the gym since there is "competition" in the class. There will be things for him to learn (double unders, triple unders if he is insane); even oly lifting.
ETA is it less $ if he quits the other 2 gyms? That is what DH and I did.
DS #1 Summer 05
DS #2 Summer 07