Three shelves
Budget: a phone or the webcam you have, a clip-on or cheap USB mic, a window or a desk lamp, headphones you already own. Mid: a better USB or entry XLR mic, a light you can aim, a capture card if a console needs one, a Stream Deck only after your scenes are annoying to click. Pro: an interface, a treated corner of the room, a camera with clean HDMI, a second PC if the first one is actually out of headroom.
The peripherals guide has specific gear notes. Match the purchase to the next six months of videos, not to a setup photo. If you are not live, you may not need a capture card at all.