Google has added updated its product structured data documentation document to include details around price drop enhancements. There is a new section named "price drop" that explains that Google "automatically calculates the price drop."
The new section reads:
Price drop: Help people understand the lowest price for your product. Based on the running historical average of your product's pricing, Google automatically calculates the price drop. The price drop appearance is available in English in the US, on both desktop and mobile.
To be eligible for the price drop appearance, add an Offer to your Product structured data. The price must be a specific price, not a range (for example, it can't be $50.99 to $99.99).
We've seen examples in the past of Google showing price drops before in search and even Google Discover. Here is an example from Brodie Clark of this in action.
Forum discussion at Twitter.
Update, here are more screen shots:
Some nice examples of the new "price drop" product enhancement on mobile in the US. 2 variations I'm seeing are: 'typically $x' & 'avg. $y'. Both are query dependent + auto generated by G. Could be interesting to test durations for each. More info: https://t.co/HUYFMwFHC9 pic.twitter.com/WoBXGyxNDj
— Brodie Clark (@brodieseo) February 15, 2021