Ann: TPG and VHA Merger of Equals Investor Presentation, page-138

Another possible influence is the spectrum auction, the longer it goes on, the more likely it is to end up at a higher price.

There was a chance there might have been only 2 serious bidders with optus excluded from most of it, which could result in bottom prices due to spectrum limits close to matching available spectrum, but if it starts to draw out that theory becomes less likely.