What part of the planning you're missing is, a portion of the door price for the gentleman guests, turns into donations to attract providers to make an appearance.
This is where if an agency throws the party, their providers profit from the event, and so does the agency.
But providers have busy schedules, and often are not going out just for the sake of going out. They will prioritize a sure paid visit over attending an event for free, even if it will better their business.
Unless in the planning stage, you have prepared a fund for donating to the time of the providers, you might not have any who prioritize the public get-together, over a paid job instead.
Just my POV.