Yes, M'am, you are right. But I have no problem with Harry. When my 4-1/2 year old can read well enough, and wants Potter...
One of 4 ways...
1. He'll be told to save for it using his allowance.
2. Make extra money doing extra chores around the house.
3. Birthday.
4. Christmas.
Library?
Also, I don't approve of just giving kids whatever they want, but books are different. There should always be novels, biographies, and interesting non-fiction at a kid's fingertips.