Dont pay more for a 131 get it chipped for £300 or tuning box for £150 and have cash left in pocket and extra gee gees!
Parkers prices arnt real world, as others have mentioned auto trader is best bet.
Also unless you need to get shot of a trade in look at private aswell as you can put a years full warranty on for £250 with www.warrantywise.co.uk which covers most items, so no point paying over the odds from a dealer just to get a warranty.
What kind of budget have you in mind?
Just my opinion but better to go slightly older and lower miles rather than vice versa.