How much time you put in depends on how devoted you are. Of course, there are differenct types of devotion. I joined my IPSC club at about the same time as a half-dozen other shooters. Four years later, I'm a B shooter. I'm in my third term as club vice president, in charge of match production, and spend about ten-fifteen hours per month on club and match activities, mostly in one weekend. Some of the other guys have never run a match, or even helped set up a match, but they've found enough time to practice to become A or Master shooters. Think about what you want and can do for the sport, as well as what it will do for you.