hitchis

Greetings, First time user so any input would be appreciated. I currently own 51 plate is200 sport and love the vehicle but I am tempted by a 55 plate is220D SE-L with high mileage, I would appreciate any thoughts on what to look out for and also if you think I would be silly to contemplate touching a 3 year old motor with 111 thousand miles. Not sure wether I can ask these questions so I apologise if it against the site rules. Thanks