The real trick is to find a friend that's a PC gamer and casually mention that you're considering building a PC. It is out of your hands at that point. The call will go out and spread like the fires of Gondor to everyone they know on Discord. Slowly but surely, used parts will begin to trickle in from others who have recently upgraded their PCs and have pieces they no longer need. A case here. Some old RAM there. A 3-4 year old GPU. Peripherals.

Like hermit crabs changing shells, their old equipment will be passed down to you; the newest convert. Eventually you will have nearly all the pieces needed for a good mid-range gaming PC, to the point where you might as well just get the last few parts to finish it. And then your journey will be complete.

As the years go by and you slowly upgrade your PC like a modern day Ship of Thebes, make sure to save all your old equipment. For there will come a time when you will hear those fateful words, "Hey, my friend is thinking about building a computer..." And the cycle shall begin anew.