Debbie, a popular wedding photographer, is able to photograph a wedding every saturday of the year. she charges couples $4,000 for a complete set of photographs that cost her $2,200 to print and develop. suppose that on one saturday debbie photographs her niece's wedding without charge, but her niece insists on paying debbie $2,200 to cover her printing and developing costs. what is debbie's economic cost of photographing her niece's wedding?