Americans plan to spend $9 billion on Halloween costumes, candy, decorations and cards this year, slightly less than they spent last year, according to new survey results published by the National Retail Federation. Last year's spending totaled $9.1 billion, according to the organization. This year, more than 175 million Americans plan to celebrate Halloween and will spend an average of $86.79 each. Halloween pet costumes are becoming more popular, according to the survey, with 20 percent of respondents saying they plan to dress up their pets, up from 16 percent last year.