I think it comes to the owner and how much work wants to be performed in order to keep it's NSX as good as new, done by a dealer/mechanic or himself ... my NSX previous owner spent a lot I have all records and the guy really did a PHENOMENAL job replacing everything that was a "bit" worn
As the records performed by the dealer show, @ 55K he not only replaced the Timing Belt + Water pump, but also the whole power steering rack, new antenna mast, all trunk seals, all fluids, alignment, etc etc ,,,,, so much more from brakes to tires etc the bill is very high ....
I am amazed and glad he did that way, no wonder my X drives straight and disturbingly perfect ... it feels as new as my 02 S2k felt when I got it with 15K miles in 05 .... all "major" servicing on my nsx was done @ 38 / 47 / 55 k miles ...
Personally I have replaced front/rear brake pads myself, oil (royal purple), oil filter, brake fluid in the last month and that could cost a lot on the dealer .... now I know doing Water pump + TB alone will be around 1.6K and that definitely doing @ the dealer as well other major things (I hope nothing goes wrong) ... again, it's all in the owner ..
Oscar