The 33% off AAA I still remember buying was GTA 5 back in 2015. At the time I was already not interested in buying games without high discounts but I gave it an exception because 1) they were selling the game+shark cash card bundle at the original price of the base game during the 2015 Summer Sale (and many people were blaming them for deceptive sales tactics due to this) and I thought it wouldn't go on a discount for a while; 2) this discount was for game+shark cash card and the original price was just the base game's price; and 3) I did intend to start playing it right away.

Then I occasionally buy AAAs at 50% -- 66% off since I thought the price was decent enough and I believed the base price wouldn't get adjusted for a while. Then I started noticing higher discounts either from Steam or digital retailers, and now the Bethesda price change. Still in my opinion the -66%s and -50%s for AAA are indeed good prices and as long as you think it's worth it there is nothing to regret.

When you see me buying games at low discount or no discount it's usually because I consider them as higher risk of being removed from Steam store. They will not be available to purchase anymore once they get pulled, but they can still be played from your library. For a game that has spent a considerable amount of time and money to develop it wouldn't make sense if they pull them from the store so soon. In some other cases I feel like buying the games and playing them to rush 100% achievements.

The sole reason for me to pre-order something will be getting exclusive items that are not available through any other means. Sometimes I do pre-order when I see the title is of interest to me meanwhile offering some exclusive stuff, more likely when there is discount. I actually have some explanation but it's really long so just ignore them if you don't want to read.

Partially this can avoid accidental activation of pre-order keys onto your account if you got the regular version. Let's say I pre-ordered Project Highrise that comes with a night light main screen and some in-game items and these are not available through other means. In order to implement this the publisher has to set up a special package that contains both the game and the pre-order DLC AppID's. Then when the game releases they have to switch the package they sell on Steam to another one that doesn't contain the pre-order DLC, and they need to do the same switch on other retail stores (e.g. Humble Store). So, let's now assume you got the regular version of Project Highrise through Humble Monthly and you activated that on your account, but later someone comes up telling you they got a special gift for you and sends you a key for the pre-order version of Project Highrise, while you--may not be aware you already have the game--attempt to activate that on your account, it will activate on your account because you don't own all of the items in the package corresponding to the key--in this case the pre-order DLC. In the end you don't get another copy of the game while you also waste a key if you don't want the pre-order items.

This is still not full-proof actually, but the same key activation mechanic applies to released games of different tiers as well. If you check the packages of some Paradox Interactive games (namely Stellaris and Tyranny) you will find the packages for different tiers of the games contain some unknown AppIDs that are not available in any other version. Let's say I bought Tyranny Overlord Edition on Steam, which is the highest tier of the game. Then I somehow got a key for Tyranny Commander Edition and if I attempt to activate this key it will activate on my account and not say "Product already owned". This is because the Overlord package contains some hidden AppID (I don't know what exactly Paradox use this for), while the Commander Edition package has yet another hidden AppID that is not in the Overlord package. And meanwhile the unknown AppID in the pre-purchase package for Overlord Edition is different from the one in the release version, so you will activate a release key of the same tier on your account even if you pre-purchased it--wasting a key without getting an extra copy.