When you get new textbooks. You still have the "new books every year or so" vs "we finally got hand-me-downs from our neighbor district after 10 years" divide.

I'd also push back against the idea that district wealth necessarily determines instructor quality. There's a lot that goes into surviving a wealthier area, and it isn't necessarily a matter of skill or experience. How well you navigate the interpersonal gamut also plays in (e.g., are you willing to compromise your ethics to keep happy the over-involved parents who care more about the grade than academic progress?).