Agree that it is wise to buy the best you can afford.
The David Clark 10/13.4 is a good headset. You can get them cheaper via the USA
http://www.pilotmall.com/productcomp...p?cat=Headsets USD 265 + USD 30 for post = USD 295 = AUD 373. The same unit is AUD 500 at a pilot shop at Moorabin. Pilotmall have headsets available from USD 110 (but dont appear to carry Altronics). I have bought a headset and a transceiver from pilotmall.
The organisation I fly with have used the Altronics as "public" headsets for some years. They work, although we are patching the headset wires every now and then when they break. The DC headset mentioned is far superior.