I think as the years go on CCs will be more and more sought after. So if you're thinking about it for a long term motor, don't worry about paying a little bit more for it. I paid about that for mine about 2 years back and I know I got a bloody excellent bargain.... But it's not like a normal GTI in that there are bits you need to spend time keeping on top of - the bits that make it special. So look after the paint, the leather, the a, b and c pillar trims, the wheels, the steering wheel and gearknob etc... You won't find any of these items ANYWHERE if they're broke, so look after them!
But yeah, what Len said. An 8v mk3 is not the quickest by a long shot. If I could, I'd have a 16v to poke about in and keep the CC in the garage more often.