It seems to me that a lot of people would visit the OZVMX site that really aren't interested in the forum, therefore the classifieds would have much more limited exposure, I know of enthusiests that were familiar with the classifieds but have been totaly unaware of the forum.
Limiting the classifieds to the forum would be better for us forum members, but not better for the value of our bikes or for the good of the hobby.
All said, it is Graeme's decision, and his work is mostly done unrewarded, so maybe its an oportunity for someone else to take over one side of it to split the workload/expenses?