Dell PowerEdge T320 Tower Server — Xeon, 42GB RAM, 10TB+ RAID 5, Windows Server 2019 — $350 OBO
Has room for 3 more drives, but requires a cable. One drive currently stuck in the bottom row due to using the wrong mounting screws on the drive tray.
No extra drive trays included beyond the 5 listed.
NOTE: THIS IS A SERVER MACHINR, NOT A DESKTOP PC!