"For example, if I bought you a gift for $100 and you thought that it was actually worth about $70 it would mean that, somewhere along the line, you’ve destroyed $30. Pop! It's gone. You might as well have just taken your cash and burnt it."

I would argue that in that case you have actually given a great gift. They have gotten something they consider valuable considering the $70 amount they would pay for it but a bit too much of a luxury given the fact that it actually costs $100.