New textbooks sold in the Uni Bookshop are horrendously expensive (www.bookshop.unsw.edu.au). Each of my four texts cost me about $80 EACH. There is a cheaper alternative, that is, to buy from the Secondhand Bookshop in Uni, where you pay 35% of the retail price, and the flip side is the book condition and availability.

It is definitely cheaper to get your requisite materials from Singapore, but that is unless you are certain that the text used is confirmed as such, and that you won't risk paying for excess baggage.