If you go to the toy store with your children and tell them that you are going to buy them something, they are going to grab anything that they want and bring it to you. You could end up spending far too much money, or you could make them sad by telling them to put items back. It is far better to give them money and tell them that they can spend all of it on whatever they want. If they know that they each only have $20, for example, they will just buy toys that they really want, that they will use.