Each October rolls around and the buzz in the school yard starts coming home strong. There always seems to be an amazing amount of competition to have the most popular characters used in Halloween costumes. While many parents and adults feel that being as low budget as possible on this costume is important, for the kids it is so much more.
So very many children only wear their costume once that it becomes difficult to justify spending any significant amount of money on it. It would be far easier to do if you could find an excuse for them to be used repeatedly. So often younger children will actually get considerably more use from them since they are still apt to play dress up.
For kids this a big holiday, and the costume that they have is a big deal. They do not take the cost into account. If they are school aged already then there is competition between kids for the best costume as well, even if only on an unofficial basis. Kids remember what they were, and what their friends were, and they remember the reactions they get from others. Having the right costume is very important for many children.