Just start with an external usb drive. You can pickup 8tb for under $200. If you want to go the extra step, you can buy two or three and physically swap them ev

Just start with an external usb drive. You can pickup 8tb for under $200. If you want to go the extra step, you can buy two or three and physically swap them every N weeks. Store the older one at a different location. Far less sophisticated than a real NAS, but also fewer moving pieces and things to go wrong.