Whats with all the scare mongering?!
I've owned my st205 for nearly 10yrs and it has never broken down, any niggles its had have been when something hasn't fbeen done quite right.
Superstrut is only that expensive if your replacing all 6 arms at once, which i've never known anyone have to do.
2nd hand turbo's can be had for £200 readily enough.
Never known a head or rear diff to go on a 205 either.
Insurance isn't too bad if you shop around, get a few quotes now to check them.
Find somebody who has one and have a go in it, you will want one afterwards though