Also, always keep in mind all of the little overhead costs that are eating away at your bottom line. I ran a busy studio for a couple of years and had no liquid assets. I closed it down and did things on my own, charged as high rates as I could get justify, always inching them up when I could, and that's when I was able to actual put something away.
The real numbers or real economics get ignored too much in PT, and pretty much all business in general but especially here, and that leads to a lot of the problems trainer's have with their businesses.
I'm always knocking how the big gyms rape their employees, but they kind of get this, and that's why they run the splits and have the quotas they do -