You can go without them for a while as you can just go to the library and photocopy whatever chapters you need to read. Sometimes it is actually cheaper to photocopy the entire textbook rather than buying it.
You would if you transferred directly to USYD. If you do a semester at UWS, then a semester at either Newcastle or Macquarie, then you can transfer into second year Med Sci at USYD.
You can't transfer directly to USYD as the Med Sci program at UWS isn't quite the same. What you will have to do is transfer to either Newcastle or Macquarie first, do a semester there, and then transfer to USYD.