Your drawing may have been a little basic for the teacher to say not to make it. Remember that there's no difference between a pool table and a coffee table except for the cost and the top surface. Both are fairly basic to make.
It's possible to make a high quality project for under $200.
You need to show exemplary skill, exemplary attitude and exemplary quality of finish to achieve a band 6. Remember that your project needs to show a wide *range* of skills.
A small, upper-end jewellery box would do this. Look at Art Nouveau OR Art Deco for inspiration. Needs to be really well finished, well designed and well executed. Hepplewhite shows similar options in his Cabinetmakers Guide, or Sheraton in their Cabinetmakers' Directory, albeit a bit bigger than a jewellery box.
Your school library and IA department would have heaps of inspirational books for making small cabinets/jewellery boxes.
Perhaps you should look at making a jewellery *cabinet*, high quality and finished appropriately, as opposed to a simple box, a'la this executed at a higher level of difficulty/more demanding requirements
Look here to find the marking guidelines for the major project - understand them well *before* you start to design and make your project.
http://www.boardofstudies.nsw.edu.au..._markguide.pdf
Cheers,
eddie