A simple example is, imagine making pizzas for your neighbors, and it takes you 15 minutes to make dough for 1 pizza, and at a $10/hr wage, that's $2.50 per pizza in dough labor costs. Now, imagine it only takes you 20 minutes to make dough for 5 pizzas. That's $3.33 in dough labor costs for 5 pizzas, or $.66/ea.
No. It means that at the 5 pizza scale, if you're selling your pizzas at $5 (assuming $3.00 ingredient and labor costs other than dough), rather than a $.50 loss per pizza ($5.00 - $3.00 - $2.50), you're now making a $1.34 profit per pizza ($5.00 - $3.00 - $.66).
The point of an economy of scale is that, once reached, it can lower costs (think quantity discounts), which means what was a loss at lower quantities can become a profitable business.
