You don't mention the age or mileage of the vehicle, but assuming it is low mileage for its age then the EGR issue may be a result of frequent short journeys. If you plan to use the car for longer journeys on a regular basis then this should reduce the likelihood of experiencing DPF and EGR issues in the future, but there are no guarantees - a more detailed inspection of the engine would be required to determine its current condition. Whether it is worth the risk or not is a matter of balancing its condition and price against other examples for sale. A higher mileage example that has been used for longer journeys may be in better health, but if this example has been maintained well throughout its life then it has the potential to be more reliable when used regularly.