So I finally broke down and got wireless headphones.
They're specifically for use with my tablet, so I can listen to audiobooks more easily. Especially given they have a... slight delay.
I also bought two more hard drives for my computer. An... 8TB internal, I think?.... and a 12TB external that apparently requires its own power (and I intend to get rid of the 4TB one I had).
I don't think I need to do any more upgrades to this thing until graphics cards advance another generation at least (at which point I'll actually be able to get double what my current card can do).