I did a thorough test (against a noise source) of headsets back in 2002 and found most of the cheap ones are basically crap compared to the Bose X, and most of them were uncomfortable to wear for more than about an hour. The David Clarke ones clamped the head like a vice - maybe good if you are doing aerobatics
If I was buying a cheap headset now I would look at some of the new models which have come on the market in the last year or two. I gather some of them are a lot better.