I made this one for my youngest sister.
I purchased the top denim fabric at a thrift store for $0.75. The other fabrics I purchased about a year ago for $1.99 / yard at an end of the season sale. I used less than half of the thrift store fabric and probably $2.50 worth of the “sale” fabrics. I also used about $1 worth of elastic and a few cents worth of thread. Oh yeah, and a button. 🙂