Sennheiser quality has been decling over the past few years IMO. Besides, I would never pay that for a headset that didn't sound any better than those. That being said, sound quality is subjective, and NO ONE here can tell you what is good for you, just what they like. Would you buy speakers without hearing them first? What works for me is just to compare specs (frequency response, Impedance etc) and do a little research. Listen to any pair you can and see what sounds good to YOUR ears.
I just picked up a new set a couple weeks ago, so I'll describe my personal search for a new headset. I previously had the plantronics set that comes with that MS voice commander or whatever it was called (bought for Tribes, but never used the puck much). I did some reading to see what was considered 'hot' right now, and most of it was simply too expensive. 70+ is too much for a headset IMO. If I'm going to spend that much, I'll get a proper set of studio monitors and gooseneck mic to tie to the headphones.
Anyway, lots of fanciness reviewed on the web. You can get an idea of things like shape, specs, features etc, but still not enough to base a purchase on. So....I go shopping and end up at the most hated of stores....BestBuy. They stock a selection of Altec Lansing, Logitech, and low-end headsets. The specs for the logitechs are all the same b/t themselves, save a few wizbang features like simulated surround sound etc. The AL sets were all pretty much equal specs-wise.
I decided the Logitechs were all too large to wear for hours on end, as full headphones make my ears sweat and ache. That, and the one set of Logitechs I was considering are those back of the head setups, and I have long hair that I keep in a ponytail, which messes with the fit of that style. If you wear glasses, the full headphones can put too much pressure on the bit around the ear. I hear studio folks complain about that.
The only difference in the Altec Lansing sets were USB vs 1/8th inch stereo, and whizbang stuff. All I wanted was a decent sound, a quiet mic, and a low price. I settled on the Altec Lansing AHS2021 set b/c it was 20 bucks, didn't need a battery, and were 1/8th inch stereo plugs. USB is fine I guess, but I use a Hercules Game Theater and I like that it shuts off the speakers if I plug in the headset, so I don't have to touch any buttons to switch b/t the two outputs (phones or speakers). They sound fine to me. Good range, comfortable, the mic is crystal clear and doesn't pick up my breathing to much b/c it has a foamy bit over the mic. Oh yeah, they were also cheap at 20 bucks, so for me, it was a win, win, win, win situation.
A long read I know, but hopefully it'll get you thinking. Good luck!