The following link has non-VPN COD: Ghosts keys: Buy Call Of Duty: Ghosts CD-Key Steam | CDKeyPrices.com
Also, check with the vendor with what you are getting. The cheapest one is a Steam Gift, and does not mention anything about a pre-order. You are likely not to get the map bonus with that one I think.
Fast2Play is guaranteeing the preorder with the bonus map at just AUD$54.49 - I am considering them now.
CJS-CDKEYS is offering the game with guaranteed pre-order bonus for AUD$62, or AUD$58 without it.
G2Play confirms they have the pre-order bonus at AUD$65.42 (at time of posting). I have used G2Play extensively before without issue and I believe you can rely on them to get the keys out promptly.
Buyer Beware of course applies. That said, I don't think any of us should be buying direct from Steam and paying the 'All Interactive' distributor tax. It is them who force Activision to charge more for Digital Distribution here as the normal Steam pricing undercuts what they sell it to the retailers for.