Recently build myself a home box from Ebay parts. Two four core Xeons, 72gb DDR3 memory and six onboard SATA ports. Two 120gb SSDs running Proxmox on that for virtualisation and a 2tb drive for misc storage. Bought an LSI 9211 HBA with another eight SATA ports for fifty euros, which gets PCI passthrough'ed to a FreeNAS VM. Four cheap 2tb drives for the initial pool.

Another VM provides an instance of NextCloud locally and that's pretty much it. Works, feels secure enough and didn't cost more than 500€ total. A four disk Synology Home NAS with drives would cost more and offer significantly less.

As for online backup, being on satellite internet makes uploading pretty much anything too painful to even consider.