Consumer, we have detected that you are above the poverty line. The 99¢ price printed on this Arizona tea can only applies to those below the poverty line. Your total comes to $3.67.
Saw an interview with a guy (on Bloomberg actually) who explained that "ability to pay" and "willingness to pay" are two different things and that the pricing system doesn't target people who have a lot of money ("ability to pay") but rather people who have fewer options.
Like, if the app knows that you don't have a car and this is the only grocery store you can walk to, you will pay a higher price.