Margaret Duffy Company has the following information available: Budgeted cost of direct materials at 900,000 units $900,000 Budgeted cost of direct materials at 820,000 units $820,000 Actual cost of direct materials at 820,000 units $840,000 Actual level of output(units) 820,000 Planned level of output(units) 900,000 The cost driver of product costs is units of output. What is the flexible budget variance for direct material costs?