That's why I suggested that the OP looking into booking with miles. Even assuming 50% discounts (very likely during January), I'd be surprised if he could manage the itin in question for less than $400 (the vaunted 2c/mile threshold).

On the other hand, during my travels out that way, I found schedule/itinerary flexibility to be a great asset. The train ride from Kashgar to Turpan (with a stop in Kuche) is really cool; it's difficult to experience the magic of the silk road from an airplane. Also, if you can make it all the way to Lanzhou over land (like I did), the ticket back to Shanghai should be quite cheap.

Moving onto the subject of weather, add me to the list of posters that questions the wisdom of going there in January. Much of Turpan's beauty and charm, for example, is seasonal; were it not for the tree-lined streets or the bike ride through vineyards to the ruins, or the spring wedding we crashed, I wouldn't have come away with such a favorable opinion.