Sulphur Crested Cockatoo For-Sale, the Lesser sulfur-crested cockatoo for sale are very docile. They can learn to speak and are easy to teach all kinds of tricks. This is a smaller cockatoo and they are sometimes referred to as the? apartment-sized cockatoo?. Lesser Sulfur-crested Cockatoo for sale. They are pretty birds with a delicate beautiful appearance and their movements are very graceful.