You only need 10 SC so if you have formed the opinion that a SYD-CBR-SYD giving you 710 SC and a year (plus probably 3 months extra) QP is not value for money then perhaps go down cheaply on
Murrays Coaches and just fly back to SYD to get you to 700 SC.
If time is, in fact, the main constraint you might also like to read
this thread 