As tough as it can be to witness, children learn by making mistakes. So you need to expect — and permit — your kids to make some questionable purchases. Relax in knowing that it’s just part of the journey toward understanding that you get what you pay for.

According to parenting expert Alyson Schafer, when faced with one of these frivolous purchases, parents need to acknowledge that the concept of value is very subjective. “Ask yourself how many pairs of black shoes you have. Then think on that when your daughter wants to buy her 10th toy pet.”

Alyson doesn’t even pretend to know what’s of value to her kids: “In September, a very specific backpack might be the most important thing in the world to my daughter. To me, it’s just a utilitarian item, but to her it could represent the key to her social standing within her peer group.

“If she’s willing to compromise on other purchases and contribute at least some of her own money, I feel obligated to admit that the expensive backpack is not a waste to her.”

Let them spend (or waste) their own money

Adults grapple with the question of value all the time: Should I buy the cheaper, generic macaroni and cheese or the brand the kids ask for by name?

But kids are just starting to learn about value and the consequences of their purchase decisions: “If I spend all my money on this awesome new video game, I’ll have the game but I won’t have any money to do anything else.”

So whether your kid decides to buy a junky toy, an expensive electronic gadget or a trendy backpack, try to keep your opinion to yourself, advises Schafer. Your child will learn more by experiencing the consequences than by being lectured about them. Eventually, he or she will be able to distinguish between the things they really want and the things they can live without.

Remember too, that if your kids are spending your money, everything will seem like good value to them. But watch what happens when they have to take responsibility for their own purchases with their own money. (If you aren’t yet giving your kids an allowance, you’ll want to read the article “Is it allowance time?”)

Set some guidelines

Obviously, having money to spend doesn’t give the kids the right to disobey the family rules. For example, if you have a “no sugary gum or soft drinks” rule, you should absolutely veto those purchases, says Alyson.

“I get my kids to make a budget detailing how they plan to spend their monthly allowance,” she explains. “If I approve $10 for their school book club, and I see that they’re not buying books but are using that money to buy candy, I remove the $10 book money from their allowance. That said, if their budget includes $5 for ‘miscellaneous items,’ that money is theirs to do with as they please.”

Birthday budget: Alyson also gives her kids a separate “birthday allowance” to buy friends’ birthday presents. “One time, my daughter was caught short because she had spent most of the gift money on herself. As a result, she could only afford to buy a very small trinket. She was very embarrassed at the party when her gift was opened in front of everyone. A tough lesson, but it only ever happened once and I didn't have to say a word.”