Understanding the cost of owning a Marmoset Monkey Owning a marmoset monkey comes with various costs that need to be taken into consideration. While the initial purchase price can range from several thousand to tens of thousands of dollars, it's important to remember that the cost of owning a marmoset extends beyond the initial investment. Some of the ongoing costs associated with owning a marmoset monkey include: 1. Housing: Marmosets require a spacious and enriched environment to thrive. This may involve the purchase of a large enclosure or the necessary materials to build a suitable habitat.