Dumpster diving can net you more hardware then you could imagine. Just look at my attic!!
Almost all AT cases I found on the streets 8 years ago.
And best is, it's all free, but you won't know what you find and if someone before you already took the good parts out. Sometimes you find zilch and sometimes you find a virgin dumped PC (I found even 3 or 4 at one time, I had to make a choice what case to bring and which ones to strip...and what to strip and I left the carcasses neatly screwed shut again.).
One word of advice:If you go dumpsterdiving, better not leave a mess or people will start disliking dumpsterdivers. Leave your carcasses, if any, in a tidy(-like) fashion 😁
And be friendly, I was gifted stuff for free when they saw me work (calmly, if you are greedy they might call the police 🤣) and gave me some more extra stuff 😁