Google Product Image Thumbnail Snippets With Pricing Overlays

Google seems to have rolled out pricing overlays on top of some product thumbnail images within the search snippets. For example, if you search for [diamond bands] and look at the Costco result, you will see these pricing overlays.

I know Google tested this some time ago, but according to Brodie Clark on Twitter, this is now live in the US search results. I can replicate it; here is my screenshot:

Not all snippets that have these product image thumbnails show product pricing, here are some that do not for the same query:

Forum discussion at Twitter.