Resellers make a shitload of money so yes,
1) It is about psychology.
2) You're projecting other peoples behavior based on your own.
3) This is a simplified explanation, but people are much dumber online than most marketers understand.
The research YOU are investing right now to sell a product, is much more than your avg buyer will do when buying a product. If you're a good reseller I'd say this is nearly always the case.
Simple example. It took me 6 months to accidentally stumble upon a vendor selling something I'd been buying over a year for 5xs the price. I knew A LOT of people buying the same thing for the same price I was. So I took that product and began selling it to them slightly cheaper. Eventually it was outlawed but that was some of the easiest money I made.
If you just look at something stupid like MMO anodes on ebay. They're rare ruthenium oxide anodes for rare chemical synthesis. Like certain forms of jewelry making. But another use they have is making explosives / fireworks. So immediately you have 2 different types of buyers. One group who is educated in electroplating and making jewelry. Then a 2nd group who just wants these things IMMEDIATELY so they can make perchlorates.
When you dig deeper, you find people selling these on websites for 2-3xs as much. Cause they know these impulsive and uneducated pyromaniacs wanna buy these things the second they hear they work for turning table salt into an explosive.
So yes, psychology plays a huge role.