Janice Company expected to sell 30,000 roses in the month of May. The budgeted cost of the roses was $45,000. The actual cost of roses for May was $51,000. Assume Janice actually sold 35,000 roses in May. Why is it difficult to interpret the difference between the expense budgeted at the start of May ($45,000) and the actual amount of expense for May ($51,000)?