"do you think it is "overpriced" to my current audio system?"
Only you can answer this question. You do have a nice system to boot, adding N10 will definitely enhance your listening experience. The overall improvements I heard in the soundstage between N100 and N10 was enough to justify the $8K price tag.
In my system, N10 sound is transparent, neutral, airy and unforced. Vocals are rich and often seductive. It's a well thoughtout server with amazing build quality. Plus, you are not limited to USB connectivity. The iPad app is best out there.
If you already made up your mind to get N10, go for it. However, common sense dictates to check out the competition at this price point. I did audition, Antipodes and Lumin servers...to my ears, Aurender sounded the best.