Why the hell set up a box gym. Get some real equipment in there, attract people who will actually use it and appreciate it. This isn't a huge money making investment. If your not doing daycare and zoomba classes your not going to compete with the franchise gyms. Bring in some real trainers, host seminars...put some oly equipment and get the crossfitters, some strongman stuff..tires...decent competition benches. You don't have the room for a small gym that's just the same as a anytime fitness or 24hr etc.