I never sell any bird that is not weaned and able to feed themselves on a variety of fruit, sprouted seeds, seeds and nuts. Having said that, if the new owner wants to continue supplementing natural foraging with a daily spoon or syringe of bird formula then I encourage it for just a few weeks. This allows the new owner to feel like they are "completing" the baby bird process to fledged and self-sufficient young adult. It also allows the bird to bond with the new owner. Hand feeding by a new owner is certainly NOT necessary for the new bird to bond with the owner. If the baby is a true hand-reared bird and bred and raised by a responsible breeder, the baby bird will welcome and even seek out contact with their new owner. The more gentle shoulder and finger time the bird has with you, the better they will respond. If you are in a family, make sure EVERYONE interacts with the bird so you do not develop a bird that becomes scared of others and screams solely for you when you leave. I tend not to sell my birds (they are expensive) to young people even after assurances by parents that they will be looked after. Too many are brought back because the young person failed to provide enough daily attention...