Might there be a better explanation? In other words, how does 99-cent pricing serve someone’s interests? Here is how economist Steven Landsburg explained the phenomenon of 99-cent pricing, in his book
The Armchair Economist: Economics and Everyday Life: The phenomenon of “99-cent pricing” seems to have first become common in the nineteenth century, shortly after the invention of the cash register. The cash register was a remarkable innovation; not only did it do simple arithmetic, it also kept a record of every sale. That’s important if you think your employees might be stealing from you. You can examine the tape at the end of the day and know how much money should be in the drawer.