I'd just like to second what everyone here said. I divorced an N, and it got ugly. He will pull out all the stops, he will lie and look good doing it, and he will manipulate and coerce if he can. I say...take your time and fight hard. Too many people have regrets later with things they agreed to because they were exhausted. It's worth the battle and it's worth the money. You're buying your complete freedom.
It's also fun to say "no" to a narcissist once you practice a little and get past the initial fear. They don't really know what to do if you don't buy into their crap, and they will rant and rave. For me, it helped me see even clearer who he was.
In some cases, if he's being unreasonable, he can be charged to pay court costs in the end.
For me, I decided it was worth losing everything we had and held my ground to fight--when my ex saw that, I think that's when the game got boring so he agreed.