Australian mobile carrier Optus on Thursday announced an extensive range of price plans for the iPhone 3G, in preparation for its July 11th launch. Pre-pay deals see the 8GB iPhone 3G marked at $729, and the 16GB model at $849; unlike most countries, there is also an option to fully unlock the device for use on other networks, for an additional $80.

Buyers looking for a contract-based 3G have a broader range of options. Optus has set a fixed charge of $23 per month for the 8GB iPhone when tied to a 12 month contract, while phones are provided for free on all 24 month contracts. Usage charges start at $19 per month for 100MB data access, and $50 of call/text credit. The middle contract plan weighs in at $79 per month, but offers an more reasonable 700MB of data access combined with $550 call/text credit. The top end of the spectrum is marked by a $179 monthly fee, but offers 1GB per month of data usage and over $1,500 of calls and SMS. Special deals for early adopters include a month of free, unlimited web browsing, or $400 of credit for pre-paid plans.