@Technowix@niu.moe You can get 4 USB drives and run RAID. Super cheap, but not great. I would probably say get a low end Intel CPU, decent mobo, case with enough drive bays and run unRAID.
@Technowix@niu.moe Depends, a proper NAS that can run some VMs and transcode video with 99,999% reliability is several thousand euro, but even a RasPi can be a NAS.