Of the items on that link, only a few are under $100, most are several 100s, and many are $1000s! With that assortment, you are still better off finding an old DVDO… Or simply buy a TV known for good compatibility.
I agree that this panacea machine of compatibility would be great if it existed, but unfortunately I don’t think it ever will exist unless it actually comes from the community itself (similarly to the origin of the OSSC and other such “retro-fan” devices).
There was some hope around the DVDO Micro for a bit, but it could never reliably do x3, iirc it also had problems with ringing and very poor deinterlacing. You can search the shmups forum for info, it’s in the OSSC thread in a couple places.
Edit: I will admit that Kramer VP-424 does look interesting, still though over $300…