The static budget, at the beginning of the month, for Onyx Décor Company, follows: Static budget: Sales volume: 1,100 units; Sales price: $70.00 per unit Variable costs: $32.00 per unit; Fixed costs: $38,000 per month Operating income: $3,800 Actual results, at the end of the month, follows: Actual results: Sales volume: 980 units; Sales price: $75.00 per unit Variable costs: $35.00 per unit; Fixed costs: $34,200 per month Operating income: $5,000 Calculate the flexible budget variance for sales revenue.