Expeditions in China or nearby

I'm visiting Beijing for the Olympics next year, and am planning to do some traveling in the region before or after. I got an offer for a three-week expedition for $4000 around the ancient Silk Road which sounds very good. $4000 all-inclusive (except for flights which are fully quoted) for three weeks sounds too good to be true; is it?

I was wondering if anyone here has experience with tour/expedition operators operating in China or elsewhere in northern Far East - not Russia -, which are reputable, experienced, and photographer friendly. To me that means doing something else than getting whisked from one sight to another for days on end in a bus. I prefer to see and photograph the sights that haven't been photographed by millions before me, although the occasional Great Wall or even a cuddly panda is ok. A few 2-3 day stops are much better than many 1 day stops.

I'm also interested to hear what I should ask for, and about, when I contact the tour operator with queries, as I've never been on an "expedition" before. I usually travel with friends with very loose itineraries, so a strict schedule on my vacation is a bit off-putting. But I'm not the backpacking type and am too lazy to set up a whole extensive trip in a country I don't know the language of all by myself.

Please note that I have traveled in China and elsewhere extensively, and I don't expect first-class accommodation or transportation. In fact, local hotels, buses/trains and cuisine are far superior to the McHilton experience. I'll get enough of that in Beijing.