Subscription is still worth it for most people though. Sure it costs more, but your 2TB plan isn't a single harddrive, it is likely across several harddrives with RAID ensuring that when (not if!) they fail no data is lost, plus remote backups. When something breaks the subscription fixes that for no extra charge.
If you know how to admin a computer and have time for it, then doing it yourself is cheaper. However make sure you are comparing the real costs - not just the 2TB, but the backup system (that is tested to work), and all your time.
That said, subscriptions have all too often failed reasonable privacy standards. This is an important part of the cost that is rarely accounted for.