Many years ago, when I was doing boxing everyday, I went to the same gym for several years. Its was a humble place: one old ring, a couple of bags and a couple of punchingballs. We were doctors, one lawyer, a journalist, a butcher, several kids from university, a taxi driver, with a former pro as a coach, another coach, a very very closed group. We would punch each other every day but we would go to war to protect each other, they are still my friends to this day. Then one day I went to a wrestling gym. Two coaches, a nice group. When I went to a jiu jitsu gym, I despised the environment: a lot of pills being negotiated near the showers, assholes with experience humiliating (sometimes even hurting) the new ones, but it was a small operation: one chief coach and two or three instructores, and not much else.
Last year I visited a gym: fitness instructors, boxing coach and instructors, jiujtsu coach and instructors, wrestling coach, one karate coach, a permanent nurse on site, all sort of machinery, weights, stationary bikes, supplements sold on the side through an endorsement contract, with special clinics on weekends for special sills (TDD, kicks, etc). All bullshit.
Of course a new mma gym will be much more expensive...