That seems really fast to be getting his next belt considering you go once a week. At my son's dojo he got his white belt pretty fast but they have a minimum requirement of classes you must attend before you even get pre-tested. He had to go to 23 classes just to be able to pre-test to green. Only if they think you're ready will you test. He's a green belt now and the requirement for pre-testing is 30-40 classes. It's getting harder as he progresses I like it this way because I want him to learn MA and not coast through the belts not knowing what he's doing. They also have set days that they do things like on Tuesdays and Wednesdays it's self-defense or the one-step. On Fridays it's sparring and on Saturdays it's Katas. They're very organized which I like. My son is in what's called "The Black Belt Club", where basically it cost me more money monthly but he can go up to 4 times per week plus I never have to pay for his testing. Even when he tests for black belt. One of the masters told me that it can run a couple of thousand to test for black belt. Do you think your son is learning anything there and deserves to move up? I would probably look around at other schools just to see how they run them and compare them to the school he attends now.