They pop up all over Sydney - fairs with tables stacked high with second hand and vintage books for sale. Lifeline runs multiple ones throughout the year, as does Fine Music 102.5. Which book fair is the best one in Sydney? Is it the one that offers the most rare books, or the one that has the most bang for your buck?
The Lifeline book fairs are great because not only do you get great books at really low prices but you know that it is going to a good cause. The best ones are ones that are at schools because they are usually quite big. There is one in July this year at Knox but for other dates check out the Hawkesbury Lifeline website: http://lifelineh2h.org.au/event_cat/book-fairs/
I love the ones that Fine Music 102.5 put on. They have such a great variety of books, from modern fiction to old cook books to vintage collectibles, and the prices are always really good. They run for a decent amount of time, and towards the end usually have one or two days where everything is half price. The one I always go to is at Crows Nest, and they put it on twice a year. I don't think I've ever missed it.