It seems that nobody has included the cost for exceeding the monthly data traffic (aka bandwidth) limits that some ISPs limit their customers to. Typically, the more you pay each month for your Internet access, the higher your monthly limit. However, if you have a large amount of data to upload to the Cloud (even if "only" 1 TB), these ISPs' charges for exceeding their monthly traffic limits could be very expensive. Combining the cost of the Cloud storage and the ISPs excess traffic charges, local or NAS storage would be FAR cheaper than any paid online storage. Of course, no extra costs if you have no monthly traffic limit.
Another consideration is the speed throttling that some ISPs impose on their customers who are consuming large amounts of bandwidth at any time (some ISPs only apply throttling after a certain threshold amount of traffic). @garth25 refers to his paid Cloud service as providing about 50GB upload over 24 hrs. If that speed is not throttled, and didn't vary due to local and/or provider traffic, it would take 3 weeks to upload 1 TB of data. If throttling applied, that could turn into months. Worse, if uploading to the Cloud affected speeds for other users on your LAN, there might be a rebellion!
Bottom line? Cloud storage doesn't appear to be feasible for large amounts of data, IMO.