Chris was referring to the place (ie Nissan) where the actual key is obtained.
Just Jap in Kirrawee does not stock the G35 Transponder type key; but if you wish to wait, they could get it in.
Sydney:-
Just Jap for instance stocks the R34 GT-R key for $129 - less discount for SAU Members
Abbotts Locksmiths can cut the key from either i) computer code which is most accurate or ii) your other key for $60
JapLink Motors can programme your newly cut key, so long as you bring your current key (for matching), for $20
All up cost would amount to $200