Good Question: Why Do We Dress Up For Halloween?This Halloween, families are expected to spend nearly $8 billion celebrating the holiday. That's a 50 percent jump since just 2005. And a lot of the money is going to costumes. Americans spend about a $1 billion on children's costumes each year, and another $1.2 billion on adult costumes. How it all got started dates back to the Middle Ages. For the folks at the Theatrical Costume Rental</a> in Minneapolis, 20 percent of their yearly business is done during the month of October. Duck Dynasty, What Does the Fox Say and Jack Sparrow are just a few popular costumes this year.