I agree with chemjim1--a lot of the "maintenance" items that the stealership throws at you don't need to be done at the 30k or even 60k check unless you are really stressing out your engine/transmission/brakes eg. four wheelin' in the mud, towin' a 5,000 lb trailer in stop-n-go traffic, etc.
Nissan dealer is a good option, esp if you don't have an infiniti stealership near you.
A honest and competent mechanic could do prolly most of the things on the premium list and with a little research and this forum-you could to.
For instance...$40 labor fee + parts for in cabin filter!: check out this thread:
how-to-replace-in-cabin-air-filter-06-0 ... 39889.html
I am no mechanic, but if you get the field service manual, can follow directions, don't mind getting a little dirty, and are reasonably handy-you can do quite a lot on your own. It helps if you have a buddy who knows a little about cars. I thought it wise to make an investment in a set of ramps and jack stands so I could do some stuff on my car, but some folks have neither the time nor inclincation to do so-diff'rent strokes for diff'rent folks.