Here's a holiday idea!
Why not this year, give your child the gift ...of maturity.
Too steep? Let me explain.
Every Christmas, your child gets tons of boxes to unwrap. So the Christmas element of excitement and surprise is well covered. They get cash gifts, too. This handles the Christmas prosperity angle. And these bills automatically make a beeline for your kid's bank account or little piggy bank.
This will make him feel all 'big boy' (or big girl). A child loves the feeling of being trusted, specially with a very huge, usually impossible financial responsibility.
This will also make him feel independent. As much as you can, try not to question his toy choices. It's his money now and his shopping time. So if he wants to buy a singing lampshade, as long as it's within budget, so be it.
This will make him learn to choose wisely between the qualities of one toy and another. Practicality is one trait that's nice to have your child grow up on. Before you know it, you'll have a tiny smart shopper in your hands.
This will make him realize the importance of money. If he used to think that you can buy just about anything for him with your presumed deep well of cash, this little exercise will open his eyes to reality. If you're lucky, this will automatically tame his inner brat.
And on an educational note, this will teach him math. Nothing sharpens your mathematical skills quite like counting money.