Not going to spend time coming up with percentages - but transportation comes to mind. You either rent a car and pay for gas and parking on top of that (not recommended at all), or you pay for taxis, Uber/Lyft and/or buses.
I can't be bothered with learning bus schedules and waiting for them - so I use Uber or Lyft to get around. I would never rent a car there.
Another huge one is Hotel Casino resort fees. You may find a room for $50 a night - then they charge you a daily fee of $25-35 on top of that. Some people don't notice that until they get there. Your $50 room will actually end up being about $85-95 a night. including fees and taxes. (Taxes are very high there).
Tips are expected from everyone everywhere and it all adds up. You will be tipping drivers, bellhops, waiters/waitresses, some people think maids should be tipped, and then tipping in the casino for drinks and in cash games. Some still ask for additional tips when you place in the money in tournaments.
Those are really the only 3 you would need to concern yourself with.