That’s why the button says “purchase” instead of “buy”
First off, they're synonyms
https://www.merriam-webster.com/dictionary/purchase#synonyms
Now, I'm certainly no expert on the US legal system. It certainly seems silly if you could circumvent entire laws just by using synonyms but what do I know.
However I have been talking about other countries where that is not the case and where the language is not English.
So It really doesn't matter whether it say "buy" or "purchase" in English when it's "kaufen" in German or "acheter" in French.
Keep in mind that "inflation going down" is usually shorthand for the year-on-year inflation rate going down.
If the yoy inflation rate goes down from one month to the next, then prices are still higher than previous year but may very well have fallen since last month.