Krysta buys what she knows what she likes up to the amount. But never buys anything that is too pricey (over $2).
Milla is worried only about buying things that are good value for money. Will buy a few big things.
Chanel wants quantity of items. So buys lots of cheap items.
Later they were talking about buying for maximum energy as they want to stay up all night and you need energy to stay awake.
In the end Chanel spent money very conservatively and was well within her spending limit. Krysta had shopped very carefully up to her limit with a minimum of spare change. Milla simply overspent by a little bit.