Looking at our NZ price watch website, I note that I can buy a Hitachi 2.5" 500 Gb drive for £107, plus an enclosure for about £4, so the £100 price looks favorable. I've read some pretty scathing reviews of Iomega external drives, so take what note you will of that. See this re the Buffalo drive:
I'd like to know what *brand* of hard drive is inside.
G4 eMac 1.25 GHz, OS 10.4.11
G3 iMac 600, OS 10.3.9
G3 b/w 350, dual drives, dual OS, 10.3.9, 9.2.2
Numerous peripheral gadgets, all working.