Why did many artisans, manufacturers, and shopkeepers in the middle colonies in the eighteenth century prefer servants' labor over that of wage workers?

they can receive more work for less pay from the servants as opposed to the wage workers

Explanation:

Based on the information provided within the question it can be said that they preferred servants' labor more because they can receive more work for less pay from the servants as opposed to the wage workers. At that time roughly four months of workers' wages would pay for about five or six years of servant labor, thus leading to a massive increase in savings for the employer.