Market Supply and Market Demand

Market Equilibrium: The point at which Market Supply is equal to Market demand.

that simple concept determines the supply is willing to ensure at a price that is optimal to them.

I buy cans of pop on the regular here on campus because I'm an addict. I usually buy from this little viet place on campus and it's so funny how often they change their price on me.

I've gone 3 times and so far I've paid three different price:

1.50
1.10
1.25

I just think it's funny this lack of consistency.