Well if you have a network at home, wired or wireless, it should be straightforward to get more storage onto it. What is less straightforward is making it squeezebox compatible, as I think it needs to be running SqueezeServer (or whatever it's called). 320gb of Linkstation will cost you less than a hundred quid, can have Squeezeserver installed (there are instructions
here for the tech savvy, can have additional drives added for backing up or more storage etc etc.
The terastation starts at a TB, adds RAID, over-spec'd power supply, hot-swappable disks blah blah - that may be overkill for you.
Nothing, like something, happens anywhere