I have a lenovo explorer and it's been fantastic. Super light, tracking is okay. I literally only use it for vrchat.

on ebay?

I'm still loving my HTC Vive that I bought second hand a few years ago for €300. The Vive is probably too low-res for most (it does have terrible "screen door" effect), but you can get the Valve Index for about that price now, based on a very quick scan of ebay listings.

In terms of budget options you can still buy new, it's probably pretty much just the PSVR2. Just at this moment you can get it for $300 direct from Sony (it's listed at $399 but it's on sale), though you'll need to buy an adapter to use it on the PC, which is an extra $60. Still, it's got a pretty decent resolution display, and it's even got eye tracking, though I think you need a third-party driver to get that working.

It is tethered, though. I dunno.

PCVR is in a slump right now, though, and at this price, I don't know that Frame is gonna fix that. It might not be the best time to buy new.

The old windows mixed reality headsets were that before it got discontinued

Windows mixed reality is calling for you. (You need oasis driver on windows)

That sadly isn't possible I don't think, loss leaders will be out of style this decade I think sadly

I mean, I sold a Vive five years ago for about $250. If you want to give up standalone gaming, and cordless, and on board speakers, and inside out tracking, and virtually all of the innovations of the last decade in this space, then I have no doubt that you can find aging hardware that still runs, at a good budget price.

Yes, tech is getting unreasonably expensive. But this product was always going to be a head above the old generations of Valve VR hardware, and I'm stoked for such a flexible piece of kit that can support streaming from my beefy pc as well as, or better than, my locked down Q3.