£5k seems a bit steep to me, I only paid £5350 for my 55 plate DCI sport. The millage was a little higher at 70k, but not far off.
I'd think more around £3500, but if someone is prepared to pay £5k, which I know people do, then fair enough.
Have you not considered a 56/57 plate old style DCI, tax will be cheaper and you should find one for around the same money.