def price_scale(definition, order)
      return definition['scale'][price_paid][0] * order.price, definition['scale'][price_paid][1] * order.price
    end
def price_scale(definition, order)
      return definition['scale'][price_paid][0] * order.price, definition['scale'][price_paid][1] * order.price
    end
Calculates the prices according to the `scale` definition.