Upload & Sell: Off
Here is my backup solution
I have 2 external 3TB drives. I use a free tool from Microsoft called SyncToy to make my backups.
My main desktop PC has 180GB SSD as my boot disk, 640GB for all my documents, files but not my photos/videos. 1TB internal HDD has all my photos, another 1TB internal HDD has all my videos.
On a regular basis (daily or weekly, depending how many new critical files have been added) I sync all the relevant folders from all my 3 internal HDDs to one of my 3TB external drive. The 2nd 3TB external drive is kept at my work location. Once a month I swap the external drives. With this approach, I will probably lose only 1 month's data if both my internal HDDs and the 3TB external at home is destroyed (like flooding or natural disaster).