Where are those giveaways coming from?

https://www.steamgifts.com/discussion/buKeD/humble-bundle-humble-seven-deadly-sims-bundle

giveaway su

It drops in Idiegala's gameplay giveaway sometimes.

This is WRONG Topic!
Try: https://www.steamgifts.com/discussions/deals

New humble bundle
https://www.steamgifts.com/discussion/7pH59/humble-bundle-humble-best-of-stealth-bundle

https://www.steamgifts.com/discussion/7pH59/humble-bundle-humble-best-of-stealth-bundle

Not many that gift that.

I kinda think it's from the Lootboy pack, the ones that are for charity - it's listed as random drop there
https://www.lootboy.de/loots/6126474c0b7e71001aa17e50

"The Premium LootCard can be one of the following cards:
(...)
FULL PC-GAME: Fling to the Finish
(...) "

https://www.steamgifts.com/discussion/xRnT9/humble-bundle-august-2021-humble-choice-21

Well you can check on Steamdb for the prices inside the steam shop or you can also check on SGTools where you have the games sales on basically all sites (and it gives you info on the games contribution value too).

Hope it helps.

Some well-known price comparison sites:
https://gg.deals/ (also lists some gray-market keyshops in results, in a separate table)
https://isthereanydeal.com/

For the grey market check these two: dlcompare and cdkeybay

For Russian shops:
https://vgtimes.ru/
https://strateg.shop/

However, there always might be region locks.

Would love to know this one as well

https://www.steamgifts.com/discussion/dbwYP/humble-bundle-humble-remarkable-roguelikes-bundle-9-x-hero-siege-dlcs-added

One group promotion, and the other user is basically a giveaway-machine, only giving, not even entering.
Nothing deal or bundle

Certain key-hub website :p

https://www.steamgifts.com/discussion/xRnT9/humble-bundle-august-2021-humble-choice-21

Yeah, I wanna know that one too.

Maybe Intel?
https://game.intel.com/ww/giveaways/minute-of-islands-game-sweepstakes

From this bundle

Key Hub (ended)

vloot.io

Gleam (ended)

Playtest from PCGamesN (today, raffle)

https://www.steamgifts.com/discussion/lNwcX/fanatical-summer-mystery-bundle

or grey sites selling it at about £1.30