Central Table Inc. has prepared a static budget at the beginning of the month. At the end of the month the following information is available:

Static Budget:

Sales volume: 2,000 units: Price $50 per unit

Variable costs: $12 per unit: Fixed costs: $25,000 per month

Operating Income: $51,000

Actual Results:

Sales volume: 1,800 units: Price $58 per unit

Variable costs: $16 per unit: Fixed costs: $35,000 per month

Operating Income: $40,600

Calculate the flexible budget variance for variable costs.