As Terry hinted, the services aren't that expensive...
<$200 for a minor service with a workshop that's familiar with Grey Import Skylines. They do not charge like specialist Nissan Dealers. More like $70-$90/Hr
Maintenance parts are not really expensive either. Oil and air filters can be obtained from Nissan. The workshop can supply high quality oil like Motul, Elf etc
Dif oil is easy to get from Autobarn, as are pads and rotors.
Availability of specialty parts is not hard via Nisswreck, Just Jap, Powerplay, Unique Auto, Toy Shop and many others.
Australia, UK, Indonesia, Hong Kong, Malaysia and Thailand are places that have absorbed export Skylines from Japan.