Thanks for your responses, just to clarify though:
Price: Yep, we are aware of it, in AUD its about 2400. For a 3 week trip, by our standards, this is dirt cheap. You can spend nearly half this on a long weekend in syd/melb by the time you factor in flights/food/accom/activities.
Passenger: We are definitley NOT doing this as rider+pillion. 1 bike each.
Experience: We currently have bikes & our motorbike licenses, with a couple years experience each.
Overall, i think you guys have confirmed what we already knew - it would be cheaper to do it ourselves, without a babysitter :-P . That said, we are happy to pay extra so we can enjoy the adventure.
Really appreciate all your feedback, imagine we will be booking it soon!
Also, whats everyones opinion on the weather at this time of year? Ive done some reseearch and it seems its just coming into monsoon in the north around when we want to go (early July)?