They sip power compared to the titans (which I had limited). I paid $110/card to my door. I only have a 2u chassis. I just got rid of my old Dell 900 series machines. Next affordable chassis for me is either an r740 or r7425 if I decide to go that route. I also need a new workstation too, was looking at the precision 7920 rigs as well. I found a pair of 2nd gen Xeons that should out perform the 3900x I have now.
Discussion
if you're doing more inference, keep an eye on the cpu's pcie lanes. amd tends to have more of them than intel, though iirc the xenons aren't bad. i'm really digging these used epyc milans though