Hello and welcome "aikawa".
Check the Maintenance Schedule in the Workshop section for Honda's recomendations regarding servicing.
25,000kms is pretty much bang on for a top-end; I'd certainly be doing it, just to be on the safe side! There is a full engine rebuild feature in the Workshop that takes you through the steps of rebuilding the top-end too.
If you're in Japan, then you are in the best place to buy an NSR! Just keep looking until you find one in your price range that meets your criteria - there's enough of them about!
Invigiator should be along sooner or later to chip in on the cost of things your side of the world, as he's in Japan too.
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Andy.
NSR-WORLD.COM
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