Valve is implementing a number of new changes to its Steam platform, all aimed at enhancing the quality of the user experience for gamers. One of the latest updates involves adding a 30-day price history to all listed games. This feature will allow buyers to see if a game's price has changed recentl...
Already mentioned but I’ll second https://isthereanydeal.com/ as existing.
That said, Valve has a fairly generous refund policy and the real kicker would be if Valve would automatically give you the better deal if the price drops within the refund window, backed up by such a feature. I heard them doing that before but it was only special cases, iirc, and the period is only 14 days but still.
At the cart window before paying, there can be a notice if the game is available for cheaper price in a bundle in example. There were a few such cases in the past, which saved me a few Euros. I don’t know if any of the other store fronts on PC does that, let alone on console.