What about the Chinese made Giant Trooper 3500, its a hybrid/touring bike, comes with 700x40c wheels, fenders, front and rear racks. Not sure of the cost, but if you could pick up an earlier, rim brake model which must still be in stock it would be less than 300USD.

http://www.giant-bicycles.com/zh-ht/....m/6741/42628/

An Italian guy and his partner rode over 7,000kms across China on these bikes last year, with no problems at all. Check their journal in cgoab:

http://www.crazyguyonabike.com/doc/p...id=112822&v=X8

I don`t know about the availability of good panniers in China, but you could get a friend to post you a set of say, Ortliebs, and maybe a set of foldable Marathon XRs and you`d be good to go.