For licensing, you would want to check with the San Diego chamber of commerce and/or the state of california. For insurance stuff, call an independant insurance broker - he or she will be able to get that info for you.

For costs and stuff, I don't know - you just have to price out the equipment, staff, etc. Are Bally's and those gym franchise companies public? If so, they have to file paperwork with the SEC and all that is public information. You could probably get some good information from their filings.

May companies like to offer gym membership to their employees but not all of them can afford to have their own gym. You could probably take a look in your downtown area and see if there are any gym facilities - if not, where would be the best place for you to put a gym? I would venture to say one of those big 100 story office buildings. See how much the rent would be, etc.

Also, I would strongly recommend that you try to talk to management of either the building or the ones occupying the office space. Would the firms be willing to pay for memberships? Would employees be interested and could you price (taking account of your definately high rent fee) the monthly fee reasonably enough to make it affordable.