For a family looking for a "cheap" run around, I think the IS is great value for money. Sure you can pay out £10k for a tiny car with good MPG. I mean your options for say a 2003 saloon car are the Ford Mondeo and Vectra, both of which will probably cost you money in maintenance. Whereas the IS so far "touch wood" has not cost me a penny, except £5.50 wiper blades.
Even with a diesel car of this age, unless you are doing a certain number of miles per year you won't get your money back. One of the sole reasons I have not purchased a new car at the moment is because there is no point. Why pay out £15k on a newer car that does 45MPG when I can keep my car which is valued at about 2.5k that does 30k. I don't work in finance but I am sure that the numbers are in my favour. Coupled with the fact I still have a lovely car that is a headturner.
Some of you may laugh when I say the Kia Magentis is another great car that has gone under the radar. Only the other day I saw an 07 automatic with about 50k on the clock marked up at 3k. Full leather interior, electric everything, V6 engine. It depends on what you want from a car, if you have got it in your head you want better MPG, pay more for the car and more on maintenance.
I think people are so fixated with MPG now as it is drilled home in such a way that the tax bands have changed, news on TV, prices going up. 30mpg is still excellent for a car of this age, considering it was probably on the drawing board at 1996/7
Dewfallsuk is absolutely right about people wanting smaller cars now, considering the roads are getting more and more smaller with allsorts of crap painted on them. Tesco reducing the size of their carpark spaces so you can just about fit a trolley in them. The big car is on it;s way out and has been for some years.