DO INSIGNIA! After working at Best Buy, they have insignia brand EVERYTHING... The employee discount on Insignia brand items is really good, but the standard prices aren't awful, depending on the item.
Here are some examples of gaming-related items:
Insignia POWER SUPPLY: https://www.bestbuy.com/site/insignia-550w-atx12v-2-4-eps12v-2-92-80-plus-bronze-power-supply-gray/5974702.p?skuId=5974702
Insignia case fan: https://www.bestbuy.com/site/insignia-120mm-case-cooling-fan-black/5976000.p?skuId=5976000
Insignia RGB leds: https://www.bestbuy.com/site/insignia-6-rgb-led-light-strip/6097914.p?skuId=6097914
Insignia cable ties: https://www.bestbuy.com/site/insignia-8-cable-ties-multi/6231005.p?skuId=6231005
Lap desk: https://www.bestbuy.com/site/insignia-17-multimedia-lap-desk-black-grey/5972802.p?skuId=5972802
Monitor riser: https://www.bestbuy.com/site/insignia-computer-monitor-riser-black/4258201.p?skuId=4258201
Wireless retro controller: https://www.bestbuy.com/site/insignia-wireless-controller-for-snes-classic-and-nes-classic-gray/6065301.p?skuId=6065301
USB microphone: https://www.bestbuy.com/site/insignia-usb-microphone/5831602.p?skuId=5831602
Insignia wireless earphones: https://www.bestbuy.com/site/insignia-ns-cahbtoe01-wireless-over-the-ear-headphones-black/5759922.p?skuId=5759922
Insignia speaker system: https://www.bestbuy.com/site/insignia-2-1-bluetooth-speaker-system-3-piece-black/5450917.p?skuId=5450917
Insignia 4K TV: https://www.bestbuy.com/site/insignia-43-class-led-2160p-smart-4k-uhd-tv-with-hdr-fire-tv-edition/6245701.p?skuId=6245701
Platinum bluetooth mouse (Platinum is another Best Buy brand):
https://www.bestbuy.com/site/platinum-bluetooth-laser-optical-mouse-black/6178120.p?skuId=6178120
Platinum laptop backpack: https://www.bestbuy.com/site/platinum-laptop-backpack-black/5494800.p?skuId=5494800
Platinum travel adapter: https://www.bestbuy.com/site/platinum-all-in-one-travel-adapter-with-2-usb-ports-black/5990901.p?skuId=5990901
Plug saver: https://www.bestbuy.com/site/insignia-3-plug-outlet-saver-black/5851694.p?skuId=5851694
And some less gaming-related items:
Insignia KEGERATOR: https://www.bestbuy.com/site/insignia-5-6-cu-ft-dual-tap-beverage-cooler-kegerator-black-stainless-steel/5733202.p?skuId=5733202
VCR head cleaner (yes they still make/sell these): https://www.bestbuy.com/site/insignia-vcr-video-head-cleaner-white/8025035.p?skuId=8025035
For the ultimate portable theater...
96" inflatable projector screen: https://www.bestbuy.com/site/insignia-96-inflatable-outdoor-projector-screen-black/5467800.p?skuId=5467800
Mini projector: https://www.bestbuy.com/site/insignia-slim-line-pico-wvga-dlp-projector-black/6254029.p?skuId=6254029
Outdoor speaker system: https://www.bestbuy.com/site/insignia-6-1-2-powered-wireless-2-way-speaker-each-gray-black/5732547.p?skuId=5732547
And other random shit:
Insignia google home speaker: https://www.bestbuy.com/site/insignia-voice-smart-portable-bluetooth-speaker-and-alarm-clock-with-google-assistant-gray-black/5865906.p?skuId=5865906
Insignia walkie-talkie: https://www.bestbuy.com/site/insignia-portable-speaker-with-walkie-talkie-black/6200211.p?skuId=6200211
And there's a shitload of other insanely random insignia products. Seriously. They have Insignia power supplies