Americans will spend more on treats, pumpkins and costumes this Halloween than they have in the last 11 years. The new poll from the National Retail Federation projects that $8.4 billion will be spent preparing for and celebrating the fall holiday. That breaks down to an average of $82.93 per shopper vs. the $74.34 spent last Halloween. $3.1 billion will go towards costumes, another $2.5 billion will be spent on the treats, and $390 million will go towards cards.