Determines the complete cash outlay (including commission) necessary
        given a quantity q.
        Second returning parameter is a commission itself.

        Args:
            * q (float): quantity

def outlay(self, q):
        """
        Determines the complete cash outlay (including commission) necessary
        given a quantity q.
        Second returning parameter is a commission itself.

        Args:
            * q (float): quantity

        """
        fee = self.commission(q, self._price * self.multiplier)
        outlay = q * self._price * self.multiplier
        return outlay + fee, outlay, fee