When Booktopia has a free shipping code (I think this is the first one this year) I usually go straight to the bargain section and see what hardcovers, boxsets or coffee table books they've got for below $20.
As the promo code is now only valid on orders over $17, I have sorted the section based on prices (books for between $10 and $20, high to low) and here are some bargains I've found:
* Renoir in the 20th Century for $19.95 vs. $40+ from overseas and $71.51 at Angus & Robertson
* Hogarth : France and British Art for $19.95 vs. $58.72 at Angus & Robertson
* Tattoos 1 - Best Of Artists for $19.95 vs. $53.62 at Angus & Robertson and $64.80 at The Nile
and some boxsets / gift boxes:
* Introducing Graphic Guide - More Great Theories of Science for $19.25
* There Is a Monster Under My Bed Who Farts (Book and Plush Toy Gift Set) for $19.95
Plus there are thousands of other titles in the bargain section. This Booktopia promotion code is valid until Monday, 20th of March 2017.