Hard drives are so cheap that I have little need to weed out old stuff. My PC (a year old) came with a 1Tb drive, and I added a second (internal) one for under $100, plus a 2Tb external SATA3 for backup. By the time I fill these up, Petabyte drives should be under $100.
Oh yes, the Inverse Moore's Law has resulted in at least two more size names: Brontobyte (1024 Zettabytes) and Geopbyte (1024 Brontobytes). See
http://www.whatsabyte.com/