I'm sorry but if someone gave me £100 and said, you can only spend this on a mouse, i'd just buy a new one of what I have now:
I like it because its just the perfect weight, nice big button each side, optical, and I can lift it like 2mm of the surface and it won't sense it's being moved, so good for like, spinning round quick in a game, or you know, when you have to slide, lift up mouse, slide.......YOU KNOW!
Like my friend bought a new £40 mouse, habu thing, and if you do that, when you're lifting it, it scrolls that way, SO Annoying, cos its TOO sensitive
.
PLUSSS, mines only like £10 now so
!