Thought I’d join the homelab clear-out and try to get rid of some excess gear. I’m based in Palmerston North, the servers are pick up only but I can post the CPU's at your expense.

IBM x3500 M4 tower server - $350

Single Xeon E5-2650 – 8 core, 2.0-2.8 GHz
32 GB DDR3 1333 RAM – 4 x 8 GB RDIMM. 8 additional empty RAM slots.
Single 550W power supply
4 x 1 GB network ports + 1 management port
IMM2 Advanced, includes remove KVM management
8 x 2.5 bays – includes 1 x 300 GB SAS drive + 1 spare caddy

More info: https://lenovopress.com/tips0852-system-x3500-m4

This has 120mm fans so is a little quieter than most 1/2u rack mount servers. Firmware has been updated. This can take a second CPU but needs an additional (and possibly unobtainable/stupidly expensive) daughterboard thing. It's been running ESXi 6.7 with no issues.

Supermicro based tower server - $150

Supermicro X8STi-F motherboard
Coolermaster Hyper H411 Heatsink
Single Xeon X5650 – 6 core, 2.67 GHz
24 GB RAM - 6 x 4 GB DDR3 unregistered RAM
Bonus dual port gigabit Intel PCI network card
No drives included

https://www.supermicro.com/products/motherboard/Xeon3000/X58/X8STi-F.cfm

Motherboard is from a 1u server so only has 1 x16 PCIe slot and a PCI slot. There is an additional x4 PCIe slot, it’s in a random place but should work if you use an extension cable/riser thing (but I haven’t tried it). Firmware has been updated. Note this board has an X58 chipset so doesn’t take registered memory.

Other stuff:

3 x Intel Xeon E5-2620 CPU’s - $20 each