I've currently got a pair of Buffalo Terastations (TS-H2.0TGL/R5) both R5'd that have all my files, ISO backups, pictures etc on.
Thing is I'm getting close to running out of disk space on one of them, so that started me thinking.

Can I sell one of the units and the 4x500Gb drives out of the second and get enough to buy 4x1TB drives (WD10EADS) and stick them in one unit and use that.

or

Sell both Terastations and get the 4x1Tb drives and build up a low power box and use Home Server or similar?

Reason I was thinking Home Server is I have a 360 and a Media Center PC and the Terastations done have a spindown feature which means the drives are on constantly, with a HSBox things can power down while not being used..