The static budget, at the beginning of the month, for Vintage Wine Company follows:

Static budget

Sales volume: $2,000$ units; Sales price: $$50\mathrm{.}00$ per unit Variable costs: $$14\mathrm{.}00$ per unit; Fixed costs: $$25,400$ per month Operating income: $$46,600$

Actual results, at the end of the month, follows:

Actual results:

Sales volume: $1,800$ units; Sales price: $$59\mathrm{.}00$ per unit Variable costs: $$17\mathrm{.}00$ per unit; Fixed costs: $$33,000$ per month Operating income: $$42,600$

Calculate the flexible budget variance for variable costs.