I wouldn't have any problems with a Cat D, but there are loads of A3s out there so unless it's really cheap and is in fantastic low mile condition then there must be others out there.
Also factor in what you plan to do with it, if you are going to keep it a few years and run it until it croaks then it's resale value isn't an issue. If you plan to move it on after a year or less then think about what it would be worth then and how much you would be paying now.