There is lots of accommodation in the vicinity of the Perth Convention Centre and Trivago has provided a list which you can see by clicking this link
Go to Trivago to get the best deal
Also Check these Out
Good Earth Hotel
Tel 1800 626 822
195 Adelaide St, Perth
3 ½ stars
City Stay Apartments
Tel (08) 9322 6061
875 Wellington St, Perth
3 1/2 star
Perth Ambassador Hotel
Tel (08) 9325 1455
196 Adelaide Tce, Perth, WA, 6001
Kings Perth Hotel: Click here to read more
3.5 star accommodation in the heart of downtown Perth.
Constitution Lodge East Perth
http://www.stayz.com.au/accommodation/wa/perth/east-perth/75339
wombat–backpackers.onetime.com/
Cheap Rooms at Wombat Backpackers.
Up to 60{bd8a1e7a756e52d6dd9114a5fec3622d8543affbcb7570d2e3b7f598d7615a85} Off in Perth!
Check these websites for more:
Air BnB: https://www.airbnb.com.au/