I hope for everything to be perfect and nice and easy to explain. Unfortunately I have found that this isn't so. There are these nasty thing called viewpoint and perception. Changes everything. You change your viewpoint and you change your perception of whatever it was you were viewing (or thinking about or visualizing).
From my viewpoint of a guy trying to generally live an honest life that letter / sales technique is quite disturbing.
However, to the salesperson who was using that technique / letter it is probably a great idea.
A person does what he feels is the right thing to do.
There is also the basic human instinct of survival. Looking after yourself. The lady mentioned could have been thinking she was doing exactly that. She felt great about it. Otherwise why did she continue with it?
The salesman 'sold her' the idea that this was a great idea for making money by using wording that changed her viewpoint of how much the stamps were worth or would be / could be worth.
I wouldn't call her stupid or even uninformed because she was reacting as most humans would to a perceived easy way out of the survival challenge.
The salesman was dishonest by omitting facts of historical appreciation of similar stamps.
I myself have been caught in this 'trap' of human thinking one way or another. It is frustrating and maddening but hopefully enlightening. You learn from your mistakes.
A lot of people have to do it that way, the hard way. That sales technique will continue to work, much as we wish it didn't.
Look at what we pay for stamps. Is 10 cents too much? A dollar? One hundred dollars? How can a little piece of paper that won't feed us or clothe us or provide shelter be really worth something?
Viewpoint and perception, if we didn't have them we probably would have left Earth by now for some 'better' planet. No, wait a minute, I mean stayed. No, we would have left. Um, er . . .

