Raising Prices on Soda

Campuses every where are raising the price of soda to a $1.25 at soda machines. Many people have complained of this because they go to a soda machine and leave empty-handed because they do not have that extra quarter to pay for a soda. There is no reason to be upset becuase you can go to Walmart for example, and buy a 2-liter of soda for a $1.00. All you need to do is get in a car and go to Walmart and get some soda, but it is not as convienant as the 20 oz. sodas in the pop machine. Do you think venders have raised their prices because there is a higher demand for 20 oz. than 2-liters?