Found this and thought it might be interest:

Professor McCusker dedicates a chapter to the colonial monetary experience in his book, How Much Is That in Real Money? After the American conversion took place, he notes that many of the colonists continued to sell merchandise in their previous monetary currency, but to pay for goods with dollars and coins. An example is the sign barbers used to post on windows offering a "Shave and a Haircut — Two Bits." The "bits" were known as Spanish silver "pieces of eight," and were worth 12 ½ cents each; thus, "two bits" equaled a quarter, and Professor McCusker says men who wanted a shave and a haircut for "two bits" would readily produce a quarter when the barber finished his work.