CNBC reported that one in five consumers who purchase bitcoin do so using their credit card. Melissa Gamez purchased a used RV with 19,400 miles for $47,300. Originally the RV sold for $72,000 with a residual value of $20,400. After subtracting the residual value, depreciation allowance per mile was $0.90. How much was Melissa's purchase price over or below the book value? (Input the amount as positive value.) Purchase price was the book value by