So then they are charging 25.3% for gratuity? That's nuts!!! Although the whole thing seems insane.
So let's look at this: $18,000 minimum for food + minimum of $5,600 in alcohol (400 people@ 2 drinks per person with average price of $7-and that is probably low with this hotel) + 31.3% tax and gratuity + $5,000 room charge
That comes to $23,600 for food and drink + $7387 tax and gratuity + $5,000 room charge = $35,987 or $90 per person at 400 people.