Not necessarily. You could have a transaction take place where the buyer and the seller both value what's being exchanged in exactly the same amount and then go through with the transaction anyway because they both find trades entertaining or have a cultural preference for doing business with each other or just both place zero value on transaction costs.
That isn't common but that doesn't mean it could never happen.
> they both find trades entertaining or have a cultural preference for doing business with each other
That is value. It is any benefit they capture which they would not otherwise.