“…the average person treats a price ending in .99 as if it were 15 to 20 cents lower.”

The tendency is called left-digit bias, when the leftmost digit of a number disproportionately influences decision-making. In this case, even though the real difference is only a penny, research shows that, to the average person, $4.99 seems 15 to 20 cents cheaper than $5.00 – which results in selling 3 to 5 percent more units than at a price of $5.00"

Why Literally (Almost) Every Price Ends in 99 Cents

https://en.wikipedia.org/wiki/Psychological_pricing

EDIT: The left-digit bias is not just pennies / cents. It applies when going from $99 to $100…$399 to $400…$999 to $1000 etc.

EDIT 2: If you have a car for sale and you want $10,000 for it are you listing it for $10,000 or $9995?

      • sparkitz@lemmy.worldOP
        1·
        8 months ago

        one fella supposedly makes this claim (Bill Bryson)

        It’s not just one fella. You have to follow the links. Immediately after Bill Bryson’s name is a link to odd pricing. If you click that it takes you to the Psychological Pricing page. Scroll down to the Historical Comments section and in that paragraph at the end it has a [22] citation. Then you scroll to the bottom of the page to see the source and you see that it was a from book published in 2012.

        So, now you have two people claiming it, Bill Bryson and Steven Landsburg.

      • ripcord@lemmy.world
        11·
        8 months ago

        I’ve found a ton of things he’s claimed in books to have really questionable sources (i.e. he makes claims and positions as truth but doesn’t mention that those things are guesses at best)