Premades actually have a better price-performance ratio than homebuilt. A friend of mine asked if I could build him a new PC for his girlfriend to play Diablo with, and I pointed him to CyberPowerPC, because they could sell him something that was like a thousand dollars less than what it would cost for me to put it together for the same performance.
I just finished a new build, by the way.
- Case: Fractal Design Meshify 2
- PSU: EVGA SuperNOVA 1300 GT
- Mobo: MSI MPG Z790 Carbon
- CPU: Intel Core i9-13900K
- Cooler: Corsair iCUE H150i ELITE CAPELLIX 360mm AIO
- RAM: Corsair Vengeance 192GB (4x48GB) DDR5-5200
- GPU: MSI GeForce RTX 4090 SUPRIM X 24G
- Storage: 2x 2TB Samsung 980 Pro M.2 SSDs, 2x 4TB Samsung 870 EVO SATA SSDs (soon to be 4x SATA SSDs, when the rest show up).
The fans are a mixture of Corsair AF120 Elites (on the AIO) and AF140 Elites, complete with eye-searing animated iCUE LEDs. The pump came with a 6-fan controller, but it wasn't enough for the 8 fans I wanted to install, so I split them across the pump's mini-Commander thing and a Commander Pro, with four fans on each one. They're nice and quiet, and it seems to be running pretty cool. The CPU is idling at 35C and doesn't seem to go over 70 under load. I'd heard the 12VHPWR horror stories about the 4000-series cards, and the NVIDIA 4-into-1 adapter was a big fugly tumor of a thing and absolutely unbearable to look at, so I got a Cablemod cable that puts the 4x 8-pins close to the power supply and shaves some bulk off the visible parts behind the window. Honestly, 12VHPWR is kind of pointless. There was no reason why they couldn't have simply engineered these cards with four ordinary 8-pin PCI-e connections along the side. They certainly have the space for it.
Overall, it turned out nice:
If anyone wants to get into DIY PC building, they should be doing it for the pleasure of it, and owning something that's built to their exact specifications. The price-performance ratio is pretty much always worse.
I've built computers for my buddies IRL, before. I always asked them, beforehand, what their budget was and what their intended use cases were. It really differs widely from person to person. Some guys want a photography or video encoding rig, other people want one for gaming, maybe this one other guy wants one for photography, and they're all just a little different in terms of what parts you should prioritize. My desktop is always a Gaming/DAW machine, so it needs to do double duty as a workstation, hence the absolutely ridiculous quantities of RAM (to load up sampled instruments with), but a gaming rig today can easily get away with having "only" 32 or 64 gigs of RAM, depending mostly on how many Chrome tabs you'd like to have open in the background. Most games primarily require GPU performance, but not all. Java games, or games with lots of physics simulations (like Kerbal Space Program or Space Engineers) tend to lean on the CPU more. The ideal CPU to run KSP, for example, is one with high single-threaded performance, since all the physics on a single craft run on a single thread (KSP's engine cannot split the physics on a single craft across multiple CPU threads, and the framerate will throttle as the CPU struggles to keep up).
For the kind of games OP wants to play, a compact MicroATX rig with an RTX 3060 and 32 gigs of RAM would be more than enough.
In fact, to play Grey Goo and Starship Troopers (and maybe the occasional AAA game on moderate settings) this is what I'd build:
It doesn't have to cost a fortune. It can be compact and quiet. This case even has a hidden optical drive bay, so you could add a Blu-ray writer and play movies or burn files off.