Time for a hard drive upgrade?

It was not that long ago that I bought a couple of 3TB HDDs for my desktop PC. Well, it has been only 2 years, as I bought them at the end of 2012 just before visiting my home country, but two years isn't that long. But I am running out of space on them.

6TB should be quite hard to fill, but the issue is, I only have 3TB usable space. One of the drives is used as a backup drive. They are not in a mirrored RAID volume though. Still, the backups are made automatically, using Microsoft SyncToy (click here to find out how). I know, I know. There is a risk of having the backup drive inside the PC, always connected. But I don't have a NAS or an external enclosure to house it. I probably should try to get one.

If you are wondering why my hard drives have been filling up so fast, it is NOT because I had been downloading torrents illegally, but because I bought a Canon 70D DSLR just before my kid was born and I had been taking photos and videos of him in full resolution. Not only the frequency has gone up, but the size of each capture is also quite large compared to the old S95 point and shoot. While I have lost the initial enthusiasm because the rapid growth of the kid has diminished, ironically the size of each capture has actually gone up. This is because even though I started with photos, the kid now moves too quickly for the camera to keep up that I have had to switch to video. When I am capturing videos though, I capture them mostly using the iPhone 5S, but the sizes are still many times that of photos.

So what shall I do?

There are only two options.

1. Replace the 2x 3TB drives with larger drives.
2. Buy two more drives (one of each model as I have right now) and make the WDC Green drives external

If I am going with the first option, the next question is, which drives should I upgrade to. Getting 4TB drives isn't worth it as I'll only be expanding the capacity by 1TB. On the other hand, 5TB and 6TB drives are very expensive, especially if you take the price per GB. However luckily for me, Seagate has come up with 8TB drives for a reasonable $260 but as I  need to get two drives, it's not reasonable all of a sudden. Plus, the Japanese prices will be even higher. Still, this is the least cumbersome option, as I don't have to mess with external hard drives. Just need them to come out in the Japanese market.

Then there is the 2nd option - buy two more drives, use the WDC Green ones as external backup drives and the Toshibas as the internal. In addition to expanding the capacity, I would be able to run the Toshibas in RAID-0, but I'm not that comfortable doing that. Just saying you there is the option. How much would it cost me? About JPY 20,000 in total for both drives, which would be much less than getting two 8TB drives and selling my existing ones.

Keeping external HDDs and manually backing up the drives every week or so would be a huge inconvenience compared to doing that automatically when the drives are internal. I would most definitely forget to backup every week and would lose some data if something happens to the internal drives. However, connecting the drives to the PC via USB wouldn't require further equipment as I currently possess one such converter, which I had to buy when I was playing with the Asus UL20A laptop.

If I choose to go with the second option, it would be beneficial to build a NAS as that would take away the inconvenience of backing up data manually. However on the other hand,  the cost would increase to the point where getting 2x8TB drives becomes the better option. This a NAS is not happening any time soon.

I guess I have to survive with roughly 350GB remaining in my data drive until the local prices of the Seagate 8TB drives are revealed. I hope that I won't have to wait a long time for that though.