Autodesk announced through web and resellers that Autodesk AEC is finally upgrading Civil 3D users on subscription to Infrastructure Design Suite Premium for free. That gives you all the Standard features including Navisworks Simulate, and adds 3DS Max.
Check with your reseller for subscription renewal upcharges next year. The quote I read was only a $50 per seat increase per year, and hey, you can try it for a year for free.
This offer is only good till July 15th, so get on it while you can.BTW… The cost of moving up to Infrastructure Design Suite Ultimate, which gives you Navisworks Manage, was not free. I have not heard exactly how much yet.