Having just lose my Plat status, I have realised at there are more things in life than a Plat card from IHG. I have looked further and found better value and better locations for the same standard of accommodation. Specifically, BW delivers the same product as HIX or HI but cheaper - even after spending up extra for points bonuses etc.
Likewise, there are other hotels that offer similar standards to the higher level IHG hotels for much less. Eg, why bother with the CP near Narita airport when hotels such as Richmond in Narita town are more convenient and cheaper?
- this is a bit lateral from the OP's question, but it seems a lot of effort to come out line ball on costings.
And, hope the stay in Sydney is enjoyable!