A company produces and sells a single product. The budgeted and actual data for the month of January are as follows: Budgeted sales volume 10,000 units, Actual sales volume 8,000 units, Budgeted selling price $50 per unit, Actual selling price $55 per unit, Budgeted variable cost per unit $20, Actual variable cost per unit $18. Calculate the sales volume variance, sales price variance, and variable cost variance. Discuss the implications of each variance on the company's performance and strategies for variance analysis and control.