So, this morning, when I poured milk into my daily bowl of cereal, the milk ran out.
Because I can't live without milk1, I headed toward La Verdes after my biology recitation2 to buy a gallon of milk. When I finally found the milk shelf surrounded by a myriad of sodas, I saw the price. $5 for a gallon, $3 for half a gallon, and $2 for a quart. For sake of completeness, the Shaw's near Random House sells milk for approximately $4 a gallon.
Seriously?! The Costco near my house sells milk for $2.25 for a gallon. I can practically get four times the milk for the same amount of money at Costco than from here. So then I thought about the problem some more:
(Assuming that walking costs no money)
Therefore we choose La Verdes milk over Costco milk at this moment, but most definitely Costco milk over La Verdes milk when I have an entire list of food to purchase.
 I drink approximately 36 ounces a day; 12 ounces at each meal
 completely useless if you have a decent background in the subject or pay attention to the lectures and read the textbook