Unit contribution = realised price − landed merchandise cost − payment fees − variable loss and support allowance − any additional sales-dependent expense. Here: $18 − $8 − $0.72 − $0.78 = $8.50. A licensing royalty or sales commission belongs in variable costs if calculated per sale; recalculate contribution and avoid counting it twice.
Monthly operating contribution = retained sales × contribution − fixed costs. Low tide: 50 × $8.50 − $720 = −$295. Steady current: 140 × $8.50 − $720 = $470. Strong-current case: 280 × $8.50 − $720 = $1,660.
Simple cash recovery = initial launch cash ÷ positive monthly operating contribution. The steady case is $9,600 ÷ $470, about 20.4 months. The strong-current sensitivity is $9,600 ÷ $1,660, about 5.8 months. Negative contribution has no finite recovery under unchanged assumptions.
Break-even = $720 ÷ $8.50 = 84.71, rounded to 85 retained sales. A 24-month target is ($720 + $9,600 ÷ 24) ÷ $8.50 = 131.76, rounded to 132 units monthly. These calculations assume stable price, unit contribution and fixed expenses.
Include actual landed cost, royalties, venue rent or commission, refill labour, travel, utilities, software, connectivity, insurance, refunds and maintenance. Opening stock is included in initial cash; ongoing merchandise cost represents replacement stock. Classify each cost once.
Examples exclude financing, taxes, depreciation, ramp-up, residual value, discounting and changing working capital. Simple cash recovery is a planning measure, not accounting ROI or a promise of commercial performance.