This is a single Walmart and clearly dominated by outlier price swings. No, NPR didn’t make their own CPI. Surely there are other independent price baskets that actually attempt to do this, why choose this article, as interesting as it is?
I am not the one making the original assertion. I was pointing out that it relies on historically trustworthy statistics that the current administration is openly influencing.
Call the NPR methodology a canary or smoke test, if you will. Feel free to grab the brass ring if you want sources that you find more credible.