Use your good judgment. There is free water, everywhere. You can bring a few gallons of it from home and it should last the trip. If you should need more, get it from the fountains at rest stops, restaurants, office buildings, stores, or anywhere else you see a water nozzle. You should not ever pay for water.
Water is a natural resource that is a gift for all humans and animals to use and benefit from.
No one should have to pay an outrageous price for water, as if it were a novelty item. There are other people who are driving around who aren t as good inside as you are. Use your instincts. You get that gut feeling for a very good reason. Make sure your car is loaded with weapons.