As mentioned above, the SkyLite/KnightTech headsets sold by David Knight on eBay are actually pretty good. I bought a couple of pairs to stick in the back for pax, and they're better than the DCs I bought during my PPL for a fraction of the price. I really don't understand why people buy them - they're horrible things. All the instructors at my local FTO moan like hell about them causing interference with other sets.
I have a Bose set these days, but given the choice there are plenty of alternatives I'd put above DCs. Don't buy a set just because all the sheep at your club have them. Go somewhere where you can make some comparisons, then make an educated choice.