What you need is more aggressive culling. Eventually more storage space becomes a black hole for a photographer. Your photos go in- and never come out, because the sheer quantity is oppressive. Who wants to spend a Sunday flipping through a thousand tiny variants of the same picture?

If you are a talented professional who takes terabytes of unique & engaging photos, disregard- but otherwise, as another photographer, let me suggest you focus on culling instead of storage.

(Photo Mechanic was a godsend for culling; it's fast as blazes even on weak hardware, and cheaper than a new processor or more DRAM)