In a study titled Inattention and Prices Over Time: Experimental Evidence from 'The Price Is Right' (1972-2019), and posted to SSRN, Jonathan Hartley of Harvard University found that the price is now wrong more often than it's right.
The study look at around 120,000 bids from The Price Is Right's One Bid contestants' row game from 1972 to 2019. It was found that contestants have increasingly underestimated the true price of goods over time, suggesting to the author that people have become more inattentive to prices.
The paper showed, via Quartz, that Price Is Right guess accuracy dropped dramatically from the 1970s to the 2000s and then stabilized into the 2010s.
Apparently a guess in the 1970s was typically about 8% below the actual price, whereas now people are underestimating prices by more than 20%.
Why? To the author, there are a few reasons why people have gotten worse at guessing the true price of things. For one, people tend to pay close attention when inflation is high and unstable, as it was in the 1970s and 1980s. Online shopping was also cited, since prices have become similar across sellers and people might not be paying close attention to do price comparisons. Also, there are more products than ever. It's hard to keep track of everything.
Just anecdotally, I can confirm my own price guesses have gotten worse over the years. When I was a child in the 1980s, I thought I'd be great on The Price Is Right because I tended to guess well. Maybe I was paying close attention to what we bought at the store when my mom was out and about, or just closely reading that Sears catalog. Over the years, my guesses got much worse.
The 2017 documentary follows longtime Price Is Right superfan Ted Slauson, who did what it never occurred to me to do as a kid -- memorize the prices on the show and keep up with the models of items typically up for bid. Back in the '70s and '80s, he noticed they often showcased the same items repeatedly. He used his memorization skills to help himself on the show but also to help other contestants, including one man who had a suspiciously perfect Showcase bid in 2008.
After that, I do wonder if The Price Is Right varied its items to such an extent that guessing became more difficult.
Anyway, the best strategy on contestants' row seems to be bidding one dollar over the previous highest bid. There was a story about one contestant that kept happening to in every round, and he finally found a good way around it.