ed*It depends on the kind of monkey you are hoping to buy. Most wild, exotic, and endangered species of monkeys cannot be purchased as pets, however domesticated species of monkeys are widely available in the exotic pet trade.
Depending on what you are looking for, you may find monkeys for sale in specialty pet stores, online, or even on classifieds websites like Craigslist. **Be sure to research the legality of owning a monkey before buying one, as some local, state, or national ordinances may prohibit the purchase or possession of certain monkey species. **