Final answer:
The important difference between doctors' private practices and other small businesses is that prices for doctors' services are set externally. Costly paperwork is necessary to secure payment for services rendered, and payments are rarely received directly from the immediate customers for doctors.
Step-by-step explanation:
The important difference between doctors' private practices and other small businesses, such as restaurants and hardware stores, is that prices (or rates) for doctors' services are set externally.
While restaurants and hardware stores have the flexibility to set their own prices based on factors like cost of ingredients or production, doctors typically have their prices set by external entities such as insurance companies or the government.
Costly paperwork is necessary to secure payment for services rendered, and payments are rarely received directly from the immediate customers for doctors, which is another important difference from other small businesses.