If you don't want to / can't afford to spend £250+ then seriously consider a second-hand headset. You can pick up a "professional" headset for the cost of a new "student" headset, it'll last longer and if you ever sell it you'll get pretty much all your money back.
A good places to look is your club noticeboard although you might find a friendly PPRuNer with a spare set (as I did, thanks IFR!).
--Mik