couldn't agree more...there seems to be a lot of confusion on this point, and I have the suspicion that there are some greedy customs officers around, trying to hit even nationals shipping their own road-legal, and previously already registered bikes back to their own country, as I read recently on an italian forum.
It Would be good to share some experiences and opinions, and if someone out there could give us a clear idea of what the law actually says.
I checked Italian law on this point when I answered a similar question a while back, and this kind of thing is what I would presume should be the same all around europe thanks to our brilliant (?) common market thing: apparently as long as the bike is imported by a tourist, for temporary use, over a 90 day period, then there are no customs fees, period.
Italian customs can charge a very high deposit in case of permanent imports, which is returned once the vehicle is permanently registered in italy, and allows the owner (italian resident) to drive on a temporary number plate.
Just to be clear, I'm talking only about customs, and not agents fees.