I'm not up in arms about the cost of gas, but Michael, in addition to what Malsua wrote, in order for your comparison to make even a little sense, all water sold by the gallon would have to cost over $10.00. As it is, you can go to any grocer and purchase a gallon of spring water for as little as 89 cents, a far cry from $10.00 per gallon.
The real fact of the matter is the cost of infrastructure to produce bottled water is minuscule compared to the costs of:
Finding an oil deposit
Drilling a well
drilling a well which actually produces oil
paying royalties to the land owner
transportation of the oil to the refinery
building a refinery
operation costs
bringing that oil to market
taxes
etc. etc. etc.
The fact of the matter is a gallon of gasoline is still a relatively good value.