They're often valuable for vastly different reasons â like the World War II-era coins minted from atypical metals, or double-printed pennies â but each one is easy to miss if you're not paying attention. See also: Californian Couple Finds $10 Million Worth of Gold Coins in Tin Can.
A subsistence economy is a non-monetary economy which relies on natural resources to provide for basic needs, through hunting, gathering, and subsistence agriculture.
Intensive subsistence agriculture is a type of agriculture that raises animals in a CAFO (Confined Animal Feeding Operation)-type operation or monoculture crops for the farmer â¦ and farm family's own use. Extensive commercial farming is the opposite of above, where food is produced for other people and for profit.y definition, Agriculture is the science or practice of farming,  including cultivation of the soil for the growing of crops and the  rearing of animals to provide food, w â¦ ool, and other products..