If I deliberately ridiculously over pay for an item to create publicity then as the buyer it explicitly doesn't have that value to me. The value isn't in the item purchased.
I think your definition of value / worth should be based on the seller, not the buyer.
That’s fair, there are cases where the transaction itself has some worth to the buyer for reputational or other reasons, independent of the item being purchased. Those are rather unusual cases, but they happen.
There are contracts that involve exchanging $1 to satisfy some legal requirement of consideration, but the relationship created is worth much more than $1. And of course there are barter transactions where items are exchanged directly without any specific valuation in money involved at all.
I think your definition of value / worth should be based on the seller, not the buyer.