Collect steam games any tips?

plenty but are you going for the 5k badge then most don't give +1

As somebody who has been chasing that dragon for quite a while myself I only have one advice for you:

Don't.

Sorry, I know that is not the advice you were looking for but sooner or later you are bound to realize how utterly pointless it is. Better to rip off that bandade now rather than after you spent several hundred dollars or even grand on it.

Fanatical or grey market

there isn't many in this list but you don't have to spent a cent for it so you might want to check it out: https://www.steamgifts.com/discussion/fZdnc/free-steam-games-that-add-1-to-steam-games

Except for some bragging rights, it don't mean nothing. There is no point in collecting games on steam since most of them are nothing but trash. I try to remove games permanently from my account sometimes, my current game count is 581 and I wish I could bring it down to 100 to 150 and wipe out the rest in a minute if I could. The only thing that is stopping me from doing that is that the whole process of removing a game permanently from steam account is very tedious. Look at it this way, should something happen to you, what was the use of spending all that money or time in games, or collecting games for that matter.

https://gg.deals/

any tips?

Yes. Don't.

You missed the bundle hausse, tremorgames is dead where you could do tasks for games, only option is keyreseller sites and even then gets expensive. Honestly i don't know how i got 10k, but expect years to get to that. :p
There is the DIG store and russian sites that will sell you games for cents but they usually don't count as +1 for steam.

I knew someone else on steam that wanted 5000 games somehow (without even the need to play) he bought alot in the last summer sale.

Not sure if this will work but can't you just play f2p game and then it will add +1 to your game list?