Can you provide more details on this. Are you looking for a backup solution for a Mac or a PC. Is it for a single user or an enterprise solution. In any case its good to have multiple backups to reduce the chance of computer and backup failing at the same time resulting in data loss. You could use a cloud backup service and a secondary external drive backup for example. A drive would cost you probably under $100, and cloud solutions can run around from free to $10-$20 per month, and greatly depend on how much data you want to store.