Hi Trinetra,
By the time I've got around to responding to this, I've tried about 8 guqins....and come to the conclusion that the greatest limitation ... is me!
Bearing this limitation in mind - here's what I found.
The cheapest ones (between 1800-5000Yuan) all sound very alike. The more expensive range of the market (10,000-18,000Yuan) I tried to convince myself sounded much better, but it was hard to tell. The shapes of the guqins were different. Some of the more rectangular shaped ones seemed to command huge prices. The finish and the build quality was highly variable. At the expensive end of the market, the guqins showed some exceptional woodcarving skills and a superb lacquer finish.
Some problems with me during testing:
1. The strings are not usually strung tight, nor even in tune in the shop. Some were loose, and I had to tune them myself, guessing as I went along
2. The strings' pegs, don't seem to stay in without a lot of pushing. The dowels just literally screw clockwise, and are held in position by the pressure of the dowel against the hole it is inserted into. Much like the pipa. On one of the cheaper ones, the right edge of the wood, or 'bridge' where the strings stretch over, had indented the wood - either the wood was that soft, or the string tension was that hard. It's not like a guzheng, which has a lip with plastic rings, to stop them from wearing into the wood, and this denting of the wood, will create problems in intonation. It was worse for some for the bass strings.
3. Some of the bass strings were a pain in the guqin. They reverberated like a dull flat untuned string, even when in key. I tried tuning about 3 or 4 using the open strings since my technique is non-existent - couldn't even get an acceptable note. Some problem with the cheap guqins I think.
4. Following the San Yin method on the guqins which could actually play on open strings, I was starting to feel really pleased with myself. Didn't last long...by the time I started trying to depress beyond the 5th Hui, I ended up just making flat dull notes.
5. The loudness of the guqin playing using any method other than San Yin, is not very loud. It is probably very good for people worried about disturbing neighbours - it is the kind of instrument you could play and not really be heard or not really disturb others. But again, it is the kind of instrument which guqin lovers say, is used to serenade oxen (implying that people like me, are too thick to understand or appreciate it).
As much loved/revered the guqin is, probably more so since some of the guqin music made it to the moon on space shuttle, to be honest, I find it an expensive load of crock. For 18k Yuan, I'd rather buy an instrument which doesn't require exclusive membership or snobbery to appreciate or learn. The arguments, that it is a cultured instrument, aren't particularly exciting if I can't play it or find a means to do so. However the clips I've seen of guqin players are beautiful, but I think it really is an instrument, which requires an amplifier, or at least, an exceptionally quiet chamber room to appreciate, and mostly, a lot of discipline with good enough Mandarin or another dialect, to understand the teaching.
I finally surmised that the cheaper instruments were quite terrible. At 5,000 Yuan, the guqin seemed very reasonable, however crude the underneath of it was (poorly finished wood; poor paint job and even poorer varnish...to say nothing of what felt like painted balsa wood....). I've seen better guzhengs at this price. I was so tempted to get it, and figure out how to play it later, however I came across a pipa at around 1/20th the price rather impulsively.
If you go to Hong Kong or the Guangzhou Province or Yangtze Delta cities, there is a wide selection of shops where you could have a look. Unfortunately none of the shops I visited have internet sales.
Maybe if you send an email to Eason and ask them to stock a few more (!) they might oblige. As a non-guqin player, although I've seen a fair range of guqins, I still wouldn't feel comfortable selecting one. Whereas some newcomers will buy a cheap instrument just to learn, and then progress, the cheap instruments are really really tacky cheap - I wouldn't bother wasting 2000Yuan on something like that, to work out if I wished to learn guqin more profoundly, when it is probably easier to stake 7 strings across a double cardboard box and varnish it, and make a temporary guqin.
No doubt since your Mandarin is as good as your English, you will have a greater ability to make sense of the guqin than I can.
Good luck
Now to go buy you some coffee! Thank you for the great plugin.