jiejie

Comments:
1) With only 8 days and 3 places (Beijing, Guilin, Shanghai), you've got one place too many but if you are determined, you'll have to speed-visit.

2) It's ridiculous to fly to Guilin just to see that city. That's not where the good stuff is. Reed Flute and especially Elephant Trunk Cave are time wasters and overpriced--you can safely skip them. The Li River Cruise is not the way I would play this--I would personally bus or car to Yangshuo (1 hour-ish) and do the boating/rafting there, also would stay there not in Guilin. There are some decent small hotels and lodges there which are lovely and serviceable if you don't need 5* amenities. All activities for Yangshuo can be booked locally and on the spot once there, at much more competitive prices. No need to deal in advance. If you want to ride a boat/raft through the karst scenery, just walk to the river and bargain with one of the ladies with their rafts, usually $10-15 per person for 2-3 hours' ride.

3) Minimize Shanghai. I would fly out of Guilin on the EVENING of the 17th which gives you one full day in Shanghai-the 18th. That's enough to hit the highlights. Skip tours of Shanghai, you don't need a tour to walk on the Bund, walk the French Concession, maybe see Yuyuan Gardens. I presume you can walk? Take a taxi? Take the subway?

4) My pricing:
--Internal flights PEK-KWL and KWL-PVG: $200 + 200 = $400 each. Might be able to get them a little bit cheaper booking online on ctrip once May rolls around, but not much cheaper. KWL is expensive to fly in/out of.
--Local transport like taxis, airport shuttles, etc, Guilin-Yangshuo etc.: $125 each (less if you use subway in BJ and Shanghai).
--Hotel: BJ ($100/night x 4) + Yangshuo ($70/night x 2) + Shanghai ($120/night x 2) = $780/2 people = $390 each. If you have points or access to good rates, Shanghai and Beijing are good places to use them. You can find cheaper hotels than this and I could certainly be comfortable on $80 per night.
--Food: $40/day each x 8 days = $320. Excluding imported wine/alcohol.
--Entry fees: $100 each for all 3 places and things you are likely to see. Might be less.
--Other sightseeing activities, esp in Yangshuo such as boating, night show, etc.: $75 each
Total per person done without the guided tours you don't need: $1400 at most. Excludes cost of to/from Korea and souvenirs. And this is far from "rock bottom" like the backpackers can do. My own personal style which is "simple but clean and comfortable" could do this route easily for $1100 max, and that mainly because of the inability to get deep discount airfares on these routes. But you have no alternatives to air travel with this short time frame.

My personal opinion is that for only 2 meaningful days in the Guilin area and the cost of getting in and out of there (high airfares), it is not a good value for money. You really need twice the amount of time to make it truly worthwhile. You might consider using Shanghai only as a connection point to your international onward, and just cutting it out entirely and putting the extra time in the Guilin area. Particularly if at some point in life, you're likely to be swinging back through Shanghai anyway (and sooner or later, everybody does).