IIRC the 'BIG' service should be at 50k, not 75.
75k is definitely a major service - gearbox oil, brake fluid, valve clearances and so on. Price for this at the Springfiled Honda branches in Newcastle is approx £500. Mine went in for it pre sale as not having it done can easily put off buyers
The 25k and 50k services are also big ones as the valve clearances get checked on these too.