All my nissan's temp gauges with a new thermostat installed needle sits dead center too 1mm below center.
Sorry bro all I can say the local dealer is simply ripping people off if your being charged over $50 for it.
Here have a look at this mate and genuine to boot.
http://patrolapart.com.au/product/ni...stat-suit-rb30
$43.57 +freight.
Your welcome bro