It looks like a 20th century piece to me but I am no expert on pottery,,!! Value would depend on the potter and like all collectables,, if anyone has interest in his work !! No matter if its the only one in existence its not worth anything if no one else wants it !! I would look at Colombia, Equador ect !! Perhaps you can track it down by the mark !! Or if you have one close,, a museum that has experience in South American culture could point you in the right direction !!