Although your points are logical from one perspective, it is still wise to consistently remember that a people without history is a lost people. Our customs and traditions as Africans depict our history; where we come from, where we've been and where we are now.
Bride price payment in some part of Nigeria is not a form of exchange, it is simply a honour appropriated to the parents of the bride. In such a situation, the father of the bride and the intending-groom move away from the eyes of the audience, and have themselves a agreement.
However, in some part of Nigeria, Pride price payment can be sufficiently termed a form of trade owing to much demand on the part of the bride's family.