The buy box prefers FBA sellers over FBM because customers prefer FBA sellers over FBM. It also takes into account length of time as a seller, feedback, valid

The buy box prefers FBA sellers over FBM because customers prefer FBA sellers over FBM. It also takes into account length of time as a seller, feedback, valid tracking, and other things that customers want. If you want the lowest price, you can easily choose that one. But most people do not, and it's silly to expect Amazon to cater to the minority at the expense of the majority.