I'm fully aware that now is not the best time in the world to build a PC, with so many parts being difficult to come by at fair market value. It gets a little easier if you're piecing together a mid-range gaming PC (at least on the CPU side of things), though, and if that's your goal, EVGA's SuperNova 550 GA power supply is worth a look.
It's on sale at Amazon for $64.99, down from its $119.99 list price. This model was selling for its full list price for the past couple of weeks, and before that, it typically fluctuated between around $75 to $105, depending on the day. The current discount is the least expensive it has ever been.
There's a lot to like about this PSU. For one, it's a name brand unit. It is also 80 Plus Gold certified, which means it is a high-efficiency model, and EVGA backs it with a generous 10-year warranty. It's always nice to see a long warranty, not just for the extended coverage, but because it reflects confidence in the model on the part of the manufacturer.
This is a fully modular unit too. That's great for cable management, and being fully modular rather than semi-module (where the main power cables are permanently attached) can sometimes make building inside tight confines a little easier.
Whether 550W is enough depends on your build. You're not going to want to try and power a GeForce RTX 3090 with this PSU, though it should be able to handle at least a GeForce RTX 3060 with no issue. Nvidia recommends a 600W PSU for the Ti variant and a 650W for the GeForce RTX 3070, though I've seen the latter run just fine on a 550W PSU (your mileage may vary, of course).