It reminds me of Beverly Cleary's spoof(?) of advice columns, in chapter 6 of "Henry and the Clubhouse."
"...Henry paused to read (the advice) column. A girl who signed her letter 'Flat Broke' said that her father did not give her a big enough allowance. Her father did not understand that she needed more money for school lunches, bus fare, and other things. What should she do about it? The smiling lady told her to talk it over with her father and explain to him exactly what her expenses were. The smiling lady was sure he would understand."
Granted, that MAY have been the fictional columnist's way of saying "I'm on to you, young lady. You just want more money for luxuries and your dad wants you to EARN the money for those 'other things.' So, earn it."
But that may well be too subtle for most kids. Chances are, the girl in that case would have thought "he already knows what I want to buy and he doesn't CARE! So why doesn't SHE care?!"
Not to mention that inflation is, in fact, something that many parents have never understood very well - so maybe the girl WASN'T asking for money for frivolous spending. Maybe she just had a father who refused to admit that prices had gone up.
But that clearly wasn't the case with Liz or Michael.