Build price from complete cost, verify the margin denominator, then test whether realistic sales volume covers fixed costs.
Build complete variable cost
Include materials, packaging, transaction charges and other costs that rise with each sale before calculating contribution.
Keep markup and margin separate
Markup divides profit by cost while margin divides profit by selling price. Use the measure required by the decision.
Stress-test break-even
Compare break-even units with a conservative sales forecast and test cost increases or discounting before finalising the price.


