All the points you list are very true, and as you stated in your last line under point 2 'Opportunity', people should ponder more the importance of that item.
I think that falling to the rhetorical wit of a salesman is very much dependent on one's willpower, attachment to materialistic goods, and degree of Awareness. All of which are somewhat intertwined. And basically all these three points exactly match your three points above.

Sellers' psychological brainwash has always been in existence but especially nowadays this is practised on a large scale.
The development and spread of AI contributes strongly from my perspective, because people are required to emulate a machine's motion sequence. So we repeat certain patterns more and more and until they get deeply engrained in us. Doing so, some areas in our brain are more active than usual, others less. Repetitive motion sequences lead to comfort and non-thinking, questioning. Simply like a machine. Yet what becomes inactive is our creativity, willpower, power of questioning things.

Even more, I found the most expensive items to be least durable and most detrimental to our Health. Whether certain technologies, clothes or food.

You surely addressed a very interesting topic! Great! :)