Would New zealand ,Australia for that matter be traditionally bound to purchase from only allies like Britian, Usa when purchasing planes as Russia and China never seems to enter the equation. They are major manufacturers after all. China seems very adept at cloning designs like the C17 and F35 they copied.
:hehe
There are potential issues with quality, as well as support costs, and for that matter the entire support chain.
IIRC at one of the Avalon airshows within the last decade or so, Russia wanted to send either a MiG-29 or Su-27/30 to participate. However, the aircraft did not participate because the aircraft was not allowed to operate in Australian airspace due to concerns over reliability.
Also the Russian/Soviet support philosophy for aircraft engines was (and perhaps still is) a bit different from how Western aircraft are supported. Again, IIRC the Russian engines need to be overhauled more frequently, which was typically done as part of a large scale overhaul activity at centralized depots. The Western philosophy is for less frequent overhauls, which are done usually at the base an aircraft operates at. Both methods have the potential to deliver similar overall efficiency, under the proper conditions. The more frequent, centralized overhauls does need a certain volume of work to be efficient which I believe India has had some trouble achieving. For nations with smaller air forces, I highly doubt the scale of work would approach what would be required to be efficient.
I have not even mentioned the risks and difficulties in either integrating Western avionics into Russian or Chinese aircraft, or adapting their avionics to mesh with Western systems.