What comes before and after the highlighted agreement is irrelevant. What you say before and after a contract does not invalidate a contract made some time between those two periods because further discussion or terms were had. A contract was technically formed, by your own clearly stated metrics, and by the information bob123 himself provided as I covered above. The instant the seller PMed bob123 a contract was formed because that act was the first act of stipulated consideration after terms were discussed and mutually agreed to.