Once you are in the cab, the price is no longer negotiable. The oldest and most talked about clich concerning Mexico. They seem inseparable. The truth is many dancers and tourists have been fine after drinking water in restaurants and nightclubs. Upscale resorts boast about their purified water, but Montezuma has put the fear of God into us Yankees and until Mexico has a national purification system, I can't recommend drinking anything but bottled water.
Bottled water is inexpensive and available everywhere in Mexico.
So here is a clich that will remain for awhile. Remember, it's not just water in its simplest form, but ordering a soft drink with ice is also a main concern. Fruits, raw vegetables and salads rinsed with water have been known to cause an uncomfortable day or two. The first time I danced in Mexico, I was sick on three different occasions. Of course, I never ate in the hotel, I was always venturing out, eating everywhere and anywhere.