Dear Mr Man,
We have (had?) a community darkroom in Chicago that, with no advertisement, had about 8-10 regular members paying $100 per month for 24/7 access. This included b&w printing chemicals. The darkroom took care of handling the used fixer. The fee was fine as the members were mostly students who only used it occasionally and the chemicals were generally donated. Unfortunately, the present operator has not been willing or able to advertise to the general public (I found out about it on APUG and the operator had never even heard of this site.). A few posts on bulletin boards in the right locations and I think it would have had a healthy membership.
I was using it because I had reason to be in the area about 3 days a week and, I'll be honest, it is much roomier than my own darkroom.
Neal Wydra