I might try Mickey on V/Line tomorrow just to see what happens. Hopefully it's free or next to nothing.
XXXXlbear: Okay, now I'm starting to understand why the free trips work. But it seems very strange to me that they would reward people for short return trips in that way - oh well, who am I to question the wisdom of Mickey. And traveling across one zone in that way; it's illogical that you wouldn't have to pay at all for doing that and as Gwiwer said a few pages back, it's probably the really complicated architecture that's to blame. But again - who am I to question it when you get a free trip.
As previously established: the unavailability of short-term tickets is a political decision, not a technical one.