if memory serves me right the m400s are all grey imports, never sold new in aus and imported as used bikes.
you are right - the ones that I have looked at in Peter Stevens have had the purple compliance plate and stated imports - and they are waayy overpriced IMO. The only ever 400 I seen that was "proper" Australian compliance bike was a 400 super sport! That was a few years ago (if my memory serves me correct....)
I am sure someone was deriding the 400 somewhere on this forum. Personally for the budget I would be looking at 600 up to 750. The only 400 I would consider would be of another make
Honda RVF400