I just set up a three-node Proxmox+Ceph cluster a few weeks ago. Three Optiplex desktops 7040, 3060, and 7060 and 4x SSDs of 1TB and 2TB mix (was 5 until I noticed one of my scavenged SSDs was failed). Single 1gbps network on each so I am seeing 30-120MB/s disk performance depending on things. I think in a few months I will upgrade to 10gbps for about $400.

I'm about 1/2 through the process of moving my 15 virtual machines over. It is a little slow but tolerable. Not having to decide on RAIDs or a NAS ahead of time is amazing. I can throw disks and nodes at it whenever.