What I ended up doing is buy 3090's in bulk from ex mining rigs, stick new fans in them and run 14 of them connected to an old Supermicro chassis using very nice PCI express splitters. I figured out just what the sweet spot was in terms of PCI bandwidth and maxed it out on RAM (512G). The end result was pretty usable and allowed me to run some of my own benchmarks without sharing any data with the usual suspects. The bigger problem was power delivery, the box had four pretty beefy power supplies running on two different phases. It's retired now because we're much too busy with other stuff but that was a lot of fun and gave me a much better angle on all these new developments than I would have gotten otherwise. Total cost of the system was less than one RTX Pro 6000 and it had a lot more VRAM. The whole thing looked terrible though :)