"both parties are choosing from among what exists."

No, one party is dictating what exists, the other is choosing. You need to re-read your last post. You say that:

  ""Both of them want to do it by choice, **because it benefits them**, in their view."" 

And you are wrong. One party, the consumer, has no real choice. You act as though this is just a great deal for both sides, which is nonsense.