I have them on my 2015 and never notice them. I'm pretty sure all CX-5's have the holes for them in the bumpers, just missing the sensors. The cost should be listed on the website, and truecar.com, for dealer installed options. Some dealers actually install random options on different vehicles, so it could be a matter of finding a vehicle that the dealer installed them on. That's how I ended up with roof rails and wheel locks, the car I wanted just happened to have these extra options installed by the dealer.
I'm pretty sure remote start isn't a part of a package because honestly, it's not that great, I mean it is when you need it, but it's an extra fob, and who wants that? And the rear parking sensors aren't integrated with any systems in the vehicle, you can't even adjust the volume on the darn things, which can become pretty annoying.