I did a one-way Suites redemption for HKG-SIN-SYD for 63,750 miles each way, with about $250 USD in taxes. IMO one of the best values on that redemption chart. In your case, SYD-SIN-PEK is worth it for the experience at least one-way (I wonder how much a one-way return is) or a round-trip J ticket is pretty close.
I'd agree it seems crazy to burn KF miles on such awards when SQ F or J awards are available.