It is like every day now that Google is testing some new feature with their hotel search results. Now, Sergey Alakov spotted something called "price insights" that aim at telling you if you are getting a good deal or not at that hotel. The deal is based on just on the price for that hotel on those dates or the time of the booking but also based on similar hotels in the nearby area.
When you view a hotel with this feature, it may show you this button telling you there are better deals:
When you click that, it takes you into the Price Insights section showing you first, nearby hotels that are less money the the one you are looking at:
Google plots the hotel you are looking at, compared to similar hotels, by date:
It also tells you the best time to book the hotel:
And the price evaluation based on the price per night for that hotel over time:
Forum discussion at Twitter.