People between the 70th and 90th percentiles feel squeezed by a lot of expenses that cost less for those lower on the scale, due to price discrimination, progressive taxation, subsidies, etc. College tuition is a good example. It's high enough to take a big chunk of the income of a 70-90th percentile earner, but it doesn't hurt as much to someone higher (spare change!) or lower (financial aid) on the income scale.