On: Western Digital unveiled its SanDisk 1TB SDXC card...

[feelix]

Yes, and they're disproportionately more expensive (ie more than twice the price of 2 500GB's) because of the aforementioned issues. It's also the bottleneck in having say 5TB SSD's that are just 20 smaller ones stuck together, because you could cram them into a 3.5 inch enclosure.

[Dylan16807 → feelix]

3.5 inch SSDs are expensive because they are primarily used in very expensive servers, and they aim for maximum performance.

If your main concern is capacity, you can easily use multiple controllers. In the laziest case just put a cheap raid controller in front.