One of the many side effects of COVID-19 has been an uptick in power supply pricing. Getting a high quality PSU of decent wattage for under $100 used to be relatively simple, but these days you're often stuck with 80 Plus Bronze models, or generic brands, or lower wattages. Right now, the EVGA SuperNOVA 750 GT is $30 off, bringing the price down to $100.
This is a fully modular power supply, and it has the capacity to support even extreme GPUs like the GeForce RTX 3080 and GeForce RTX 3090. About the only way you'd max out its 750W rating would be heavy overclocking and/or connecting a bunch of storage devices. Basically, anything outside of HEDT setups should be fine.
EVGA SuperNOVA 750 GT Gold: was $130, now $100 (opens in new tab)
EVGA's power supplies are well regarded, and this fully modular 750W model is capable of powering just about any reasonable PC, and it's 80 Plus Gold certified.
It includes dual 8-pin EPS12V cables, which are becoming required on many high-end motherboards. EVGA also backs the SuperNOVA 750 GT with a seven year warranty, providing peace of mind. It's not clear how much longer the deal will last, but if you're looking to build a new PC in the coming months, this should provide what you need.