Try this for second hand books in your area Textbook Exchange
Alternatively book depository or amazon can be cheaper as well. (I got one last semester $50 cheaper at book depository)
I am not studying nursing but I have found that there are usually on 1 or 2 copies of the text book at the library and you can't borrow it for a semester and they are generally in high demand. "Technically" it is against copywrite to copy as much as you will need and there is no guarantee that the lecturer will give you a reading list in advance either.
I tend to buy my books cheaply or 2nd hand and then sell them afterwards which pays for the next round of books. Unfortunately you still have to outlay or the 1st round. Also be careful if the uni bookshop comes with computer codes for anatomy etc. If you buy second hand, it won't come with the codes and you may have to buy access separately which may negates the 2nd hand discount.