Find a power supply you're interested in, then look it up on
this list...
Off the top of my head - if the OEM that makes the supply is Delta, Seasonic, or Super Flower you will be good.
I think there are 2 other OEMs that tend to always be good, but I can't remember off the top of my head. Hopefully others here will know.
Other common OEMs like FSP (Fortron Source) and CWT (Channel Well) can also make good supplies - but they also make a ton of "cost downed" ones that... aren't so good. You'll need to look at testing reviews for those - and by that REAL reviews that actually scope the PSU on the bench, and
not just "it worked for the 15min i tested it, and it's shiny - 10/10 AWARD" reviews.
The holy grail find would be finding say a 750w Delta built supply for $75 somewhere, regardless of what brand is selling it. Also if you find that, HOOK US UP
Examples that sadly seems to be gone was newegg closing out their older Rosewill Capstone supplies - Super Flower was the OEM, and the non-modular 750w was $85.
Another was the Antec 750W TP-750C for $80, + $30 MIR. That one happens to be Seasonic.
It honestly is a PITA to cross reference everything, but you can save some good change with some luck and persistence. Worst case at least you'll know what your actually buying.
Almost forgot, also might want to be sure at what temperature a given PSU is rated for at it's stated voltage. Most will be "XXXw @ 50C" some 40C. Neither is really a problem, but Corsair kinda stepped in it when they rated their CX 750 for only 30C. This may or may not make a difference to you depending on where your PSU's air intake will be pulling from. If your case has your PSU pulling air from inside your case - then that really COULD be a problem.