As tempting as it might be, don't cheap out on your power supply. It's not the flashiest piece of hardware, as it doesn't trace rays like some GPUs or hammer compute workloads like your CPU. But it does keep those parts ticking. Even though you shouldn't skimp on a generic unit of questionable quality, you don't have to pay full price, either. There are frequent sales, like this EVGA Supernova 850 G6 model that is marked down to $124.99 on Amazon.
That's $55 below the list price, which was the going rate on Amazon through the month of August and into half of December, according to CamelCamelCamel's price tracking data. It dipped in price to $140 a couple of weeks ago, and has now fallen even further.
That's good news if you're in the market for a high quality PSU. According to TechPowerUp, EVGA is sourcing its G6 series from Seasonic, a reputable manufacturer in the PSU space, and is based on the company's Focus Gold platform. Hence the lengthy 10-year warranty, which suggests EVGA is confident in the design.
This is also a compact model measuring 3.39 x 5.9 x 1.57 inches (HxWxL), with fully modular cabling to help maneuver in tighter setups and, when the build is finished, reduce cable clutter. It's also nice that most of the cables are flat, save for the main 24-pin ATX cable.
As an added bonus, EVGA bundles a power-on self tester. This replaces the paperclip method to test if a PSU is working, and while hopefully you'll never need its service, it's a potentially handy item to have on hand.
What about the wattage rating? 850W is enough to power any consumer graphics card on the market (if you can find one), including AMD's flagship Radeon RX 6900 XT and Nvidia's top-of-the-line GeForce RTX 3090.