Given my recent push to find a feasible solution for my photo library, which resulted in the purchase of a Drobo (three, actually, but that’s beside the point), I’ve gotten to know a bit about hard drive prices. Here are my two cents on the issue.

Keep in mind that this advice is applicable only during the present time, since prices will continue to fluctuate and larger hard drives will become available, driving down the prices for the smaller ones. Let me also say that if you didn’t get your hard drives before, during or after Christmas, you missed out on some great deals.

Right now, the most economical drives (best size to price ratio) are the 500 GB ones. You can get great SATA drives with 16 MB caches (current standard size), 7,200 rpm and 3.0 GB/sec transfer speed at $120 (retail-boxed; OEM drives are cheaper).

If you must get a drive smaller than 500 GB, you can, but it’s not economical. The price per GB starts to go up once you go smaller. It’s about the economics of the thing. Regardless of the actual size of the drive, the price of the components and labor has to be factored in. Even if the drive is smaller in size, and it stands to reason that it should be cheaper, it costs money to put it together, and that cost is fairly inflexible. That’s why you may gasp when you look at the prices of 40 GB or 80 GB drives (if you can still find them) and you wonder why they cost so much when no one uses them anymore.

Back to bigger drives. I remember just 1-2 months ago, the 750 GB hard drives were double the price of the 500 GB ones, but the prices are coming down. In just another few months, or even less than that, they will close the gap and become the most economical drives you’ll find. That time isn’t here yet though. Right now, the least expensive 750 GB drives (retail-boxed) I can find start at $199. If 500 GB can be gotten for $100-120, then, proportionally speaking, 750 GB drives should be $150-180 in order to be as economical as the 500 GB drives. Not yet.

➡ Updated 2/27/08: The 1 TB (1,000 GB) drives have just dropped in price enough to be just as economical as the 500 GB drives. I’m very surprised that it’s happened this fast. The market has leapfrogged the 750 GB drives, as I thought it would. I’ve seen the WD 1 TB SATA drive pictured below for as as low as $230.

The 1 TB (1,000 GB) drivesaren’t economical yet, either. It’s likely that in 6 months or so, they’ll get to be great deals. It’s even possible that market forces will cause the prices to leapfrog over the 750 GB drives and push the 1 TB drives to the forefront. Right now, the least expensive 1 TB drive comes in at $260, which is more expensive than if you were to get two 500 GB drives. Keep in mind I’m talking strictly about the GB to price ratio here, not the convenience of having a single drive instead of two, which trumps the price difference somewhat.

Because I have a Drobo, I’m isolated somewhat from having to worry about whether I have a single drive or two drives. I can still get plenty of space if I stuff my Drobo with four 500 GB drives, then replace them with 750 GB or 1 TB drives later. Or, even better, I can take the wait and see approach. Right now, there’s plenty of space on the Drobo that stores my photo library, even with only two 500 GB drives inside. That means I can wait till the bigger drives get cheaper and buy an extra drive at that point.

Similarly, the Drobo that stores our movies and videos, plus our various other files, is doing just fine with three 500 GB drives. I don’t think I’m going to fill it up in the next month or two, and that means I can wait until the 750 GB drives, or maybe even the 1 TB drives, become economical.

With hardware, it’s about striking the balance between what you must have, and what can wait. Thankfully, even 500 GB is a ton of space for most people, so it’s a buyer’s market, as they say.

Another thing you can look at, once you know the prices of internal hard drives, is the prices of external drives. When you know how much an internal drive costs, you can subtract it from the cost of an external drive and figure out how much you’re paying for the enclosure and design alone, and whether it’s worth it to buy it.

This is why I said that the 500 GB LaCie drive was a bargain, and why I recommended that people buy it. Given that you can get a 500 GB drive for $100, and the drive costs $118 (at one point it cost only $109) you know this is a bargain. You’re paying only $18 to get the drive packaged nicely in a great USB 2.0 enclosure that makes no noise. Having fiddled around with plenty of enclosures in my time, I know a great deal when I see one.

By the same token, when you look at the G-Tech Quad Interface 500 GB drive, you know that’s not a bargain. When the drive itself costs only $100 and you pay $270 to get the drive and the enclosure, that means you’re paying $170 for just the enclosure and the quad interface. Is that worth it? You decide.

Don’t think I’m implying your decision has to be guided by price alone. While I dislike paying a premium for a product, I do it if I think it’s worth it. I think the Drobo is overpriced. I still bought three of them and I recommend them to others. I think Apple products are overpriced, but I still buy them and recommend them to others. (You’ll have to excuse my tone in that post — I was seriously irritated with Apple at the time, but what I said was true.)

It’s just that it’s worth knowing what you’re buying. If you’re going to spend your money on something, then you should do the research to back up your purchase decision. This is also why I’m steamed up about Apple’s non-transparency when it comes to their hardware specifications. I don’t know what I’m buying, and it bothers me. It doesn’t mean I don’t want to buy, it’s just that I’d like to know where my money’s going.

I hope this has been helpful to you.