I had to buy a handful of components so I guess it counts
Built my first PC recently. Mostly it's my wife's old components after a few years of upgrades stuffed into a new case, but it's new to me. Pretty much just had to buy the case, a hard drive, PSU, CPU cooler, and a couple fans.
It's not a powerhouse by modern standards (though it was pretty beefy for its time when my wife first built it) with a pre-ryzen amd CPU, and a 970, but it's still running most of what I've been throwing at it (it helps that most of my steam library is 10+ years old)
We're a little short on space in our house, nowhere to squeeze in another desk for a computer so I built it in a HTPC case and I've been gaming on our 70" TV with surround sound with our hue lights synced up to it, and it's been pretty sweet, and astonishingly it hasn't burst into flames from being crammed in my entertainment center with limited airflow.
It's nice to be back to PC gaming, and I'm having almost as much fun tinkering with it and getting everything set up how I want it. Still a couple more tweaks to make, gotta figure out how I want to set up KODI, need to get a decent wireless keyboard and mouse, maybe a couple more controllers, find a way to enable HDMI CEC control so I don't need to fiddle with the PC and receiver volume separately, etc. and then maybe some more upgrades when budget allows