Cath, If margin of safety is 20% and breakeven revenue is $200,000, then what will be the budgeted sales? i guess 200000÷0.8=250000 and selling price as described above is $10 then budgeted sales units = 25000 according to my calculation We need to increase variable cost to $5.2 (from 4) in order to achieve breakeven, this represent 30% increase in variable cost.