Should be easy, if you want to go anywhere but Sydney...
Assuming you want to minimise point usage, and only want ~115 SCs:
16k QFF + cash:
HBA-SYD-CBR JASA 16k+$75.03. Add a normal MEL-HBA economy for $109, and a normal CBR-MEL for $115. Visit HBA and CBR for a total = 16k+$300 for 120 SCs.
MEL-SYD-HBA JASA 16k+$297.78 earns 100 SCs, add a normal HBA-MEL economy back for $109. HBA total = 16k+$406.78 for 110 SCs.
MEL-SYD-ADL JASA 16k+$302.64 earns 100 SCs, add a normal ADL-MEL economy back for $105. ADL total = 16k+$407.64 for 110 SCs.
MEL-SYD-CBR JASA 16k+$234.76 earns 80 SCs, add a normal CBR-SYD-MEL economy for $224. CBR total = 16k+$458.76 for 100 SCs.
24k QFF + cash:
MEL-SYD-BNE JASA 24k+$162.51 earns 80 SCs, add a normal BNE-SYD-MEL economy for $221. BNE total = 24k+$383.51 for 100 SCs.
32k QFF + cash:
MEL-SYD-CBR JASA 32k+~$470 earns 160 SCs. CBR total = 32k+$470.76 for 160 SCs.
MEL-SYD-HBA JASA 32k+~$600 return earns 200 SCs. HBA total = 32k+~$600 for 200 SCs.
MEL-SYD-ADL JASA 32k+~$600 return earns 200 SCs. ADL total = 32k+~$600 for 200 SCs.
36k QFF + cash:
MEL-SYD-PER JASA 36k+$163.92, earns 120 SCs, add a normal PER-MEL economy back for $245. 36k+$408.92 for 140 SCs.
48k QFF + cash:
MEL-SYD-BNE JASA 48k+~$320 earns 160 SCs. BNE total = 48k+~$320 for 160 SCs.
In any case it looks like you'll need to spend at least $400-$500 cash, unless you want to spend more points (and value the extra points at ~1c/point)