If you can't afford 0.15 % worth of overhead, using very conservative numbers, you need to rethink your business model. To break out that tired old analogy agai

If you can't afford 0.15 % worth of overhead, using very conservative numbers, you need to rethink your business model. To break out that tired old analogy again - you're spending more than that on coffee for each of them, when you make it yourself and don't even factor in the depreciation of the coffee machine.