What can happen if buy a key from a 3rd party site?

[Calf_]

Long story short, I want to buy a steam key from a 3rd party website to get a game no longer available from the steam store (Poker Night 2, if you're wondering). I've tried to search up what can happen to your account if the key ends up being fraudulent. In most places, people say the worst that can happen is the game is removed from your account, but I've also seen some places say your account can get suspended/banned, or even hacked. Can anyone shed some light on this matter? if its only the game gets removed, I'm cool with that as the key only costs around 1 dollar, but I really don't want to risk losing my account over it.

If it is a possible suspension or ban, is there anyway to get your account back (and without any account flags or whatever), or would my account just be ****** forever?

[Ogami]

If its a shady reseller there are 2 possible consequences.

A: The key does not work at all and you wasted your money
B: They key was stolen or bought with stolen credit cards or similar, then the game can
be removed from your account at some unspecific point in the future.

But apart from that nothing can happen, i had a few games removed over the years, not even from 3rd party resellers but bundles where the developer got into a beef with the bundles provider and revoked the keys later on.
You just get a message that the game was removed for payment problems and that you should contact the 3rd party reseller.

Thats all. Nothing can happen to your account.

[MalikQayum]

nothing happens to your account itself, meaning it wont get banned.
to keep it short, if you use a third party site to buy keys from which is perfectly fine, it means that valve won't issue any sort of support for that purchase, that support you need to find with the third party.

valve only handles support for purchases done through the steam store.