All prices are negotiable. If you buy in bulk, I can offer you a better detail (i.e. if you are just an advanced student and by both the Preliminary and HSC textbooks I can sell both for $50). I live in the Sutherland Shire, otherwise I am willing to post them to you if you pay for shipping 
TEXTBOOKS
'Maths in Focus' - Mathematics Extension 1 HSC Course: $30
- excellent condition, only used by one person, covered in thick plastic (which is removable), no markings on any of the pages
'Maths in Focus' - Mathematics Preliminary Course: $30
- excellent condition, only used by one person, covered in thick plastic (which is removable), no markings on any of the pages
STUDY RESOURCES
Success One HSC Mathematics, 2014 Edition: $25
- brand new, never been used, no markings or torn pages/edges, excellent condition
Excel HSC Mathematics Study Guide: $15
- only been used by one person, pretty good condition, no markings on any of the pages
TEXTBOOKS
'Maths in Focus' - Mathematics Extension 1 HSC Course: $30
- excellent condition, only used by one person, covered in thick plastic (which is removable), no markings on any of the pages
'Maths in Focus' - Mathematics Preliminary Course: $30
- excellent condition, only used by one person, covered in thick plastic (which is removable), no markings on any of the pages
STUDY RESOURCES
Success One HSC Mathematics, 2014 Edition: $25
- brand new, never been used, no markings or torn pages/edges, excellent condition
Excel HSC Mathematics Study Guide: $15
- only been used by one person, pretty good condition, no markings on any of the pages