ok, before you open a gym, here are some questions you need to think about, some food for thought so to speak.
Is the area that you plan to start a gym, blue collar? I ask this question because chances are if you are trying to open a hardcore gym, you need to make sure that it will attract the right crowd of people.
White collar folks simply don't want to get shit between their toes. Case in point: the last gym i trained at Marco's Powerfactory was in a pretty white collar area, but it ran out of business, the gym i train at now is a very blue collar neighborhood and is definitely attracting the right kind of people.
I know that not so many people think of that but it is soo true. it is far more simple than people think, psychology plays a huge part in how us humans think, that's why gyms like Metroflex, Westside Barbell, Nazareth Barbell, etc. are in blue collar areas.
Another thing to consider is p.r. (public relations) by that i mean use a website like EliteFts, or even nastrongman to attract some big names to your gym. If you can get someone like Ed Coan, Jesse Marunde, or Hugo Girard(since he lives in Canada) to train at you gym, many hardcore lifters will be interested.
Also go to local powerlifting, and strongman meets, maybe even boxing or wrestling matches and talk to them about your gym. Pretty soon word will get around, and you should attract the elite, hardcore crowd.