Here are some accommodation options if you are coming to Melbourne from interstate. As this is also GrandPrix weekend, accommodation options may be a little tight.
Rydges on Swanston
701 Swanston st Carlton
>From $300
http://www.rydges.com/hotel/RVCARL/Rydges-On-Swanston-Melbourne.htm
Downtowner on Lygon
66 Lygon st
>From $220
http://www.downtowner.com.au/
Darling Towers
233 Collins Street
>From $205
http://www.darlingtowers.com.au/
Parkville Place Apartments
124 Brunswick Road
>From $165
http://www.parkvilleplace.com.au/
Drummond Serviced Apartments
371 Drummond St
>From $160
http://www.drummondapartments.com.au/
Parade Inn
539 Royal Parade, Parkville
>From $135
http://www.paradeinn.com.au/
Space Hotel
380 Russel St
Dorms from $33
Or privates from $65
http://www.hostelbookers.com/hostels/australia/melbourne/4584/
The Corkman Irish Pub
160 Lecister Street, Carlton
Dorm beds available for $27
http://www.corkman.hostel.com/
Melbourne Metro YHA
78 Howard Street, North Melbourne
Dorm beds available for $34
http://www.yha.com.au/hostels/vic/melbourne/melbourne-metro/
St Arnaud Hostel
99 park street
>From $50
http://www.starnaudguesthouse.com/