I mean I'd count that as outright stating it, and also that its something she's done more than once, but are we really surprised?
This also shows she's not nearly as poor as she likes to LARP as, because to someone who's actually poor, 8 bucks vanishing is a huge deal. It's the difference between dinner being food and dinner being a deep breath.
Stephanie can't be bothered though, and she's got enough money to just throw away on anything she wants to the point that she's more annoyed and pissed off at the idea of being told to get the mistake fixed than the fact that she was overcharged by 8 dollars.