Dan Warne of APC Magazine wrote that 300Gb is the sweet spot for hard disks, where it has lowest $/Gb at 47 cents.

Are you looking to upgrade your desktop PC’s hard drive? Of course you are! There’s no such thing as too much disk space on a desktop PC.

The current sweet spot is 300GB for 47c per GB: a Western Digital 7200RPM drive for $142.00.

$142.00 for a 300Gb WD hard disk is certainly very cheap, and he has researched the price with PC parts search engine staticICE, which I have previously reported here. I have just paid $80 for an 80Gb drive 3 months ago, and I bought two at $1/Gb to set up a RAID1 mirror. I could have spend a bit more to get more space…

However the assumption is that there’s no such thing as too much disk space on a desktop PC, but there certainly exists something as enough space on a desktop PC. I now have a 80Gb RAID1 file server, and I have only filled up 30% — that’s including the operating system, our family photos of last 5 years, all my files + emails I kept since 1997… I do not download or keep MP3, video, etc, and have just felt difficult to fill the space up. So I figured, instead of spending more to get the best bang for the buck, I can actually save myself a few $$$ by getting just enough storage for the next 3 years (of drives’ warranty).

Of course, your mileage might vary. If you have a habit of downloading and keeping lots of warez Linux distribution ISOs, then take Dan’s advice and get that 300Gb monster (or two of them to form a RAID1 if you value your data). Otherwise, think about how much space you really need.