Marmoset monkeys cost about $2,500-$4,500. The species of monkeys form a generation of ‘New World’ monkeys, while other species of monkeys lack this attribute. Coming from the Callithrix breed of apes, marmoset monkeys are great as pets. Baby marmosets are available at lower prices, but rarely under $1,700. They come in a number of variations, which include the white tufted, Pensillata and hybrid marmosets. Popular across the United States, Marmosets are known to be available in many places of Florida.