"The manufacturer, however, would have adopted the machine only if it had either made a better suits for half as much labor, or had made the same kind of suits at a smaller cost. If we assume the latter, we cannot assume the amount of labor to make the machines was as great in terms of payroll as the amount of labor that the clothing manufacturer hopes to save in the long run by adopting the machine; otherwise there would have been no economy, he would not have adopted it."
it is very long winded it means what Chris said.
The text is unnatural and contains grammar and vocabulary errors.
In brief, the text says that the company purchased the machine because the payroll savings were greater than the cost of the machine.