I received the following email in response to a question about reduced flights and extra baggage when flying out for good as I was unsure whether it was just available when you got your visa verified for the first time, thought it might be useful:
Thanks for your response. Just to clarify, will my family and I still be eligible for a discounted one-way trip and additional baggage next December if we have already stamped our visas with a return trip arranged by ourselves next April? Many people I have spoken to are unsure whether the discount only applies to a first trip.
Yes, you can avail of the IOM fares next December as you did not book with IOM on your first travel to Australia in April.