No offense. You're asking a majority of owners who haven't even started upgrading their audio systems yet, and the car has been out 3 months. A few owners took matters in their own hands and did the install themselves, and the rest hired a local installer who never worked on a 370Z before either (first for everything). That's not enough to tell you what the possibilities are. Labor costs vary by shops, so we can't simply tell you the costs. IMO, $550 is too much. I've seen simple installations costing $50, but that doesn't mean you can find it in your locale.
Anyone who do their own installations are pretty much guinea pigs right now. Heck, even my local installers aren't aware of the 370Z let alone have immediate access to the service manual.
You can't assume people will spoon feed and give you answers about your car without taking a look at it yourself.
For example, I have all of my audio components purchased and ready to be installed with the 370Z. I've done lots of research and derived knowledge from the 350Z.
The car is too new and the best we can do is provide you some audio experience and ball park figures closely related to tried and true 350Z audio builds.
So take it as it is. You're in the group of "firsts" to pursue an audio upgrade project on your 370Z, so we're pretty much in your shoes and are willing to learn from those who attempted the install themselves. Take some pride with your project, enjoy, and do some research on your own. We'll provide you the best of our knowledge, but you can't force it out of the community. Patience...
When I start working on my installations, I will try to provide information and photos. My components are stored until the car arrives. From the looks of it, the 370Z audio install is so much easier than the 350Z due in part it doesn't require special adapters for double-din installations. The only catch is the speaker box.
__________________
|