Well... not considering the price, you could say they are just taking gradings more often to check if students are getting on with what is being taught. The amount of time to get to black belt is in the required boundary, Considering the fact that there is enough time in between for learning katas, perfecting stances, understanding concepts and kihon. I am not fit to judge money wise, because I am not from the particular region or even dojo. Every dojo has its own circumstances, The sensei might have to pay a large amount as rent, or maybe money for their certification or things like maintaining the dojo. If it doesn't have any of these other needs to fulfill their is a possibility of it being a McDojo or Money minded martial artist. It is to be said to ensure that he is a certified instructor before joining.