Turnup USB audio mixer

(https://www.turnup.tech/img/Labelled.jpg)

Simple USB voume control box. Are there any other options for these out there anywhere for cheap or is this gonna be my diy project for a little while? I feel like there has to be something out there for cheap that isn’t being price gouged AS FUCKING STREAMER EQUIPMENT!

check out PCPanel — a bit backlogged I think due to the pandemic, I placed an order with them about a month ago for a ‘pre-order’ and just days ago received notification that they are working on shipping the orders. The device is nearly identical to you what linked.
I can’t comment on it’s functionality personally just yet as obviously I don’t have it in hand, but I can update once able. There are reviews for it on YT though.

Yamaha AG-03 (or AG-06) might work.

Or you use something like Voicemeeter and a MIDI controller.