This property specifies the minimal quantity and rounding increment that will be the basis for the billing. The unit of measurement is specified by the UN/CEFACT code attached to the gr:UnitPriceSpecification via the gr:hasUnitOfMeasurement property. Examples: - The price for gasoline is 4 USD per gallon at the pump, but you will be charged in units of 0.1 gallons. - The price for legal consulting is 100 USD per hour, but you will be charged in units of 15 minutes. This property makes sense only for instances of gr:Offering that include not more than one type of good or service.