I didn't have my camera with me for this but it inspired me to start doing some sneaky shenanigans with my gear since.
I was visiting Toronto for a week last year for a concert and decided to walk to Budweiser Stage from the opposite side of the city so I ended up at the venue like 4 hours early. They must have thought that I was a vendor but it was great because I was was able to watch the artist warm up for ~45 minutes before the head security person figured out I wasn't supposed to be there. I was still allowed to hang around the event inside but just not by the stage. I got some free food and merch from helping some vendors set up since I had nothing else to do for a few hours.
Because of that I have started doing some light googling prior to going into buildings/events and printing out some fake buisness cards/press passes for news stations, advertising agencies, parent companies and more. The combination of that and a cheap safety vest has given me access to photograph a bunch of interesting places. If you plan to do this please be respectful, if you are asked to leave or are figured out just cooperate and leave quietly without making a scene. Also know that you may not be able to get back into the event even as a paying customer depending on the security personnel.
There are way too many variables to give a price range, you will need to price everything out yourself. Each of these could cost anywhere from free to tens of thousands of dollars. If you had much more specific questions like "recommended model agency in city XYZ for $XYZ" then someone may be able to point you in the right direction but you will still need to do the legwork.
What country are you in?
Are you flying domestic or international and how many people need to fly?
Are you hiring people local to you or from the your shoot location?
Are you getting help from friends for hair, makeup, nails, stylist or do you need to hire someone for each? Amateur or pro?
How many days is the shoot?
How many models and outfits for each model?
Are you using amateur models or high dollar professionals?
How many lights and how powerful do you need?
Are you buying or renting lighting, lenses, props, etc.?
Are you renting studio space or is this outdoors?