Other cars and their in the area have no impact on insurance though £1,000 for your self seems pretty reasonable but were getting side tracked on this insurance thing.
.
Buying a car and running a car are two completely different things. General running costs on something like a 197/200 will be a lot higher than on a Fiesta. Things such as fuel costs, servicing costs and general consumables (tyres, brakes etc) will all be higher and that's on top of the £30 per month extra you'll be paying out for insurance. I've a friend with a Zetec S fiesta (current shape) and in town driving (he lives in Derby) he's currently getting 39mpg, that's close to 25% better that you'd expect on a 197/200. Road tax will also be more on the Clio. Just things to remember. Adding it all up it could easily cost a minimum of £80 per month more.