If you are looking for Budget accommodation in Sydney, Jo Henwood has put together a list of venues and prices.

Budget Accommodation Sydney CBD

To help you book a hotel in relation to the conference location see the map below.
The conference is in the Learning Centre of the Royal Botanic Garden Sydney, with the presentations in the Maiden Theatre of that building.     The closest entrance is the Woolloomooloo Gate on Mrs Macquarie’s Street/Art Gallery Road, on the left, just past the overpass over the Cahill  Expressway, from the direction of the Domain and Art Gallery.