Covenience/Cost/Life expectancy of storage media [closed]

I may decide to pick up the battle of advocating for the use of external hard drives instead of Blu-ray discs for data backup.

External hard drive:

I can get a commercial (consumer) 1TB hard drive for about 150 bucks, and backing up consists of merely "dragging and dropping" the filesystem. The media is portable (if a bit larger) and reliable. I can have two physically separated hard drives for added redundancy (total cost: about $300).

Blu-ray

A 50GB disc costs 35 dollars in Amazon. I also need to transfer the files to the computer which has the burner, then create the images, then write them, and then store a multitude of this guys in boxes, keep a catalog, and make sure whoever takes one places it back.

Our data is critical (I guess like everyone else's).

So, if you ONLY have these two alternatives, which one would you take?

Always the HDD, the reasons simply being the costs.

I always create at least 2 sets of backups, and again the HDD wins hands down for they're easy to keep in sync.

As fo the life span, i'm sure, Cranberry (or someone else) will come up with a Bluray-equivalent to the DiamonDisc (the "1000 Year DVD") but again, this will be VERY costly affair.

With HDDs life expectancy is not so much an issue as they'll get replaced rather regularly as we move on with faster technology and bigger drives anyway. You wouldn't safeguard some 10 years old 20 GB IDE hard disk drive and worry about the data on it, you'll copy the content to some TB 'monster' disk and dump the old clunker :)

Just for the simplicity of it all, I'd go with the hard drive. It costs less and saves a ton of time, and time is money.

To get 1TB in those discs, you'd need 20. 20x35 = $700.

You may want to consider backing up to internal hard drives as well. They are less expensive and you can buy an enclosure for them all.