ChipFlip
Two 1300W Gold fully-modular supplies, $3.69 apart. The SeaSonic PRIME 1300 Gold asks $80.00 used and the EVGA SuperNOVA 1300 G2 asks $76.31. On paper these are the same product. In practice one of them is a much better buy.
SeaSonic PRIME is the better platform
The PRIME line is SeaSonic's flagship: tighter voltage regulation, better ripple suppression, and a 12-year warranty when bought new. SeaSonic also builds units sold under other brands' names, so their platforms show up across the market under different labels.
The G2 is a good supply too, but it's an older SuperNOVA design and it was built by Super Flower rather than in-house.
EVGA's warranty situation is the real difference
EVGA exited the graphics card business and has scaled back significantly. That doesn't void existing warranties, but it changes the practical calculus of buying a used EVGA unit where the warranty may not transfer and the company's long-term support posture is uncertain.
For a component whose failure can damage everything downstream of it, that's worth more than $3.69.
Both are more wattage than most builds need
1300W is a lot. Unless you're running a 5090 with a high-core-count CPU, or multiple GPUs, you'll never approach these numbers. Buying this much capacity used is a fine way to get a high-quality platform cheaply, but don't mistake the wattage for a feature you need.
Check the age either way. Capacitors degrade, and a decade-old supply of any brand is a different proposition than a two-year-old one.
Bottom line
Take the SeaSonic PRIME. Better platform, better regulation, better long-term support outlook, and $3.69 is not a price difference. Ask both sellers how old the unit is before committing, because on a used power supply that matters more than the badge.