Hi Jas
Book there. It's cheaper.
You have afew options:
(A)Drive around free and easy on your own. Look for accomodation only 1 hour before sunset. At least you get to look at the room before deciding.
This is my preferred method.
(B) Book with the tourist info counters in Melb. They will help you call and book according to your preference, budget and requirements. Small fee of $2.50 per booking i think. The star-rating of that hotel / motel will also more or less tell u the standard of that place. RACV ratings of 3-star and above is V good enough already (clean, decent, affordable). 4-star is quite luxurious. FLAG also has some ratings there (the tourist info counter staff will help u).
(C) If you're travelling in summer, accomodation may pose a prob. What i did was to bring along the Lonely Planet guide book. When i set off in the morning, i call up to place a reservation in the town that i THINK i should reach by sunset. By afternoon, call again to confirm / withdraw the booking.
(Then again, there are PLENTY of B&Bs and motels along the Great Ocean Road. The less fussy u are abt the accomodation, the easier it is to find one.)
I think i stayed in Port Fairy also ... v few accomodation avail there. If you want to secure a room there while you're still physically here in S'pore is either to call them (IDD charges) or internet bookings (some of them dun have website i'm sure!)
When are you going?
(Sorry if i had asked u before, i'm v forgetful ...)