About the rise in price - it isn't about where your factories are, it isn't about being directly affected by the flood : it's a simple balance of demand and offer. If there's less total production, each remaining element is more desirable, and thus more pricy (plus, as there was a shortage panic, demand rose too, thus price++).
About the price ratio - I guess you're right - if you have the treasury for it, you should always get the highest volume, they usually have a better To/$ ratio. I just purchased a Western Digital 2To at 129€, which makes it about 180$, 90$/To (I guess you shouldn't complain about US HDDs being overpriced...). Though the price does include warranty (3 years for me. Yours?)
About the size restriction :
Wasn't it a question of architecture - that 32bit systems couldn't handle enough addresses ? (Scratch that, it was a RAM issue.) It's a both a FileSystem and a BIOS issue :
FAT32, that powered the Windows systems up to NT (not included), used 32 bits for sector number, meaning there could be 2^32 sectors, so (2^32)*512 bytes, thus 2To. Since NT, Windows' systems have used
NTFS, which can handle up to 16 To (and theorically up to 16 Eo).
But you're right, there is also the issue of the BIOS : the Bios uses the
Master boot record (MBR) which handles the partitioning of the disks, couldn't affect to a disk partition a size higher than 2To. The current standard,
GUID, resolves that problem, and has a legacy layer to be used with older systems.
As far as I can tell, the 'worst' that could happen is either
- The disk's partition isn't recognized
- The disk's partition is cut off at 2 To
And both issues could be handled by manually partitioning the disk (using of course a different computer) into partitions of <2To.
From what I've seen, most legacy issues have been though of, but you should ask a local hardware professional - your vendor, perhaps, if they have sellpoints/showrooms ?