This has small echoes of what Mutiny (mutinyhq.com) is already doing. I think their pitch is basically "we segment who's coming to your website and then show different versions of the landing page", but I do think that they're moving into some different areas (e.g. Automatically writing copy using GPT3 to target specific users). Source: over 1 year ago

Asking if you should buy a game now or wait for a sale isn't allowed, asking when a game will go on sale is not allowed, asking how big of a discount a game might get is not allowed. Use SteamDB to look at sale histories on games. Source: 7 months ago

Here's how to cure you from your buying habit, checkout https://steamdb.info/, check the price history of the game you're thinking of getting. Most likely it's on sale once every odd month, and discount percentages are only ever increasing over time. So really you can just buy it when you think you have time to play it soon. Source: 7 months ago

Correct, it's trending on https://steamdb.info/ if you look at the panel, some games will show zero players. But OP is wrong, other games are trending too. Source: 7 months ago

Asking if you should buy a game now or wait for a sale isn't allowed & asking when a game will go on sale is not allowed. Use SteamDB to look at sale histories on games. Source: 7 months ago

You can use the Steam console to download older versions as described here. You can get the depot and manifest IDs from SteamDB. Source: 7 months ago