If you dont already live in Europe, it may be cheaper to buy/rent a detector once you are over there, your friend may know of places to get one. The expense of transporting it back and forth may need consideration. There will be groups over there who specialize in metal detecting and battlefield finds. A friend of mine went last year and met some guys in Normandy who led him through areas with metal detectors and allowed him to dig up items and even presented him with a paratrooper helmet he found.