External (Raid) Storage

I've exhausted the storage on my my d2 Lacie hard drive and I've been recommended a LaCie 2Big Quadra Raid external hard drive to back up my DV, music and personal files. A 2TB is about £300. Does it make sense? Are there cheaper ways of obtaining the same duplicating backup? Any other advice greatly appreciated.

Thanks

Could you just buy a couple of external 1TB drives and simply manually copy your backups to both of them for simple redundancy rather than using something like RAID 5 ? Boring, but cheap.