I just went this route to build a ML workstation. I was able to get a prebuilt with a 3090 for ~30% of a comparable build on https://lambdalabs.com/.

Now I just need to wait until next year to get the second 3090. I considered waiting for the new A4000s to launch to see if they'd have better inventory but figured 3090s have additional value as a gaming gpu.

I'd be curious how professional ML folks are fairing and what they're using -- it's not too late to cancel my build.