The concept of 'selling' a child doesn't really take into account the complexities that modern IVF techniques have introduced in relation to who the baby actually belongs to.
In Britain there is widespread consensus (about 3 in 4 surrogates, even), that the law needs to change in order to reflect the fact that the baby they carry often isn't genetically their own. Ironically, the law that exists today was brought into place to protect egg donors. Now, there is merry chaos. Our delightful surrogate's husband was, much against his will, legally the father of our baby. Although supportive of his wife, he had not been involved in the surrogacy arrangement, in the IVF treatment and was not related to our baby. My husband, on the other hand, could not even go down on the baby's birth certificate as the father. Yet as far as the surrogate and her husband were concerned, they didn't want another child and didn't have another child. That left our child in legal limbo. We were the 'real' parents yet for a considerable portion of our child's life, the people with parental responsibility didn't want it and the people who were actually related to the child and bringing it up didn't have it. hat's all a bit archaic and had the potential to become hopelessly messy if, say, our surrogate's husband had been a different kind of person and decided to exploit the situation.
I'm going into all that because there is a similar misunderstanding on these threads about 'baby selling'. Now that we have IVF (and it's against the law for the surrogate to be related to the child she is carrying), it is possible to carry a baby that isn't yours. It's not like a kidney, which is actually part of your body and is your own organ.
That introduces an ethical minefield about the rights and wrongs of someone using their body as a 'carrier', which to my way of thinking is a more appropriate ethical debate than 'baby selling', which is more about child trafficking than selling a child who was never going to be your own.