I find the 3 and 4 liter bottles of water are the same price at most gas stations. Of course the 3 liter bottles are on display where they are easy to find, while the 4 liter is hidden where only the price sensitive will find them. (4 liters is also one us gallon, and one you have a container you find one gallon refills vending machines that a very cheap, and those vending machines probably have better water)