A combination of two airlines, similar to this deal
https://www.ozbargain.com.au/node/815102
All flights are return and include carry-on luggage.
NOTE that it is 2 'stops'
Scoot to Singapore
Saudia onwards, stopping in Jeddah (2 to 9 hours)
Have personally been to Jeddah airport, wasn't there long but it is pretty modern.
Understandably, 2 stops is annoying but 1 stop to North Africa is quite a bit more expensive (Emirates, Qatar, Etihad…)
Example Dates:
PERTH to EGYPT
- Perth to Singapore on Scoot 10 Feb to 27 Feb $343
- Singapore to Alexandria on Saudia 12 Feb to 25 Feb $585
- Total is $928
PERTH to TUNISIA
- Perth to Singapore on Scoot 8 Feb to 29 Feb $335
- Singapore to Tunis on Saudia 10 Feb to 27 Feb $640
- Total is $975
PERTH to MOROCCO
- Perth to Singapore on Scoot 10 Feb to 24 Feb $358
- Singapore to Casablanca on Saudia 12 Feb to 22 Feb $653
- Total is $1011
MELBOURNE to EGYPT
- Melbourne to Singapore on Scoot 15 Feb to 2 Mar $432
- Singapore to Alexandria on Saudia 16 Feb to 29 Feb $586
- Total is $1018
MELBOURNE to TUNISIA
- Melbourne to Singapore on Scoot 15 Feb to 1 Mar $468
- Singapore to Tunis on Saudia 16 Feb to 27 Feb $610
- Total is $1078
MELBOURNE to MOROCCO
- Melbourne to Singapore on Scoot 5 Feb to 22 Feb $512
- Singapore to Casablanca on Saudia 7 Feb to 20 Feb $695
- Total is $1207
- Mess around with the dates and better deals are probably available
SYDNEY to EGYPT
- Sydney to Singapore on Scoot 1 Feb to 27 Feb $507
- Singapore to Alexandria on Saudia 2 Feb to 25 Feb $587
- Total is $1094
SYDNEY to TUNISIA
- Sydney to Singapore on Scoot 2 Feb to 26 Feb $507
- Singapore to Tunis on Saudia 3 Feb to 23 Feb $640
- Total is $1147
SYDNEY to MOROCCO
- Sydney to Singapore on Scoot 2 Feb to 26 Feb $507
- Singapore to Casablanca on Saudia 5 Feb to 22 Feb $653
- Total is $1160
- Mess around with the dates and better deals are probably available
WARNING
Because you have two separate bookings, if you miss the Saudia flight due to a Scoot delay you'll be stranded in Singapore.
Best options are to give yourself a 1 to 2 day buffer in Singapore and/or use appropriate travel insurance.
Not sure it's worth the hassle being on different tickets. Unless you're doing an overnighter in SG (as OP mentions).