Nice that they knocked $400 off but that's still a LOT of money. It wouldn't be worth it to me. It comes with speakers and the USB charging ports. To install, you have to remove the passenger seat the lift up on the rear (body colored) cover then gently pull it off the bike. You might have to wiggle it off one side at a time. Be careful. It will crack. Once that's off, you'll see a rubber cover just behind the passenger seat in the middle of the bike (side to side). Lift that rubber cover off, place the OEM top case in the right area and plug the connector from the top case in. The top case will have the same horseshoe shaped parts like your base model cover. Slide those in just like you would be reinstalling the base model cover and push down on the back of the top case. You'll hear it click into place. WAIT! You're NOT quite done yet. Inside the top case in the middle, there's a circular locking piece. Twist it to lock. It may be REALLY tight. You can loosen the nut on the bottom about a turn if you need to. Once that's locked in place. reinstall the passenger seat and test out the speakers and center mounted light.
I know you said you weren't interested in an aftermarket top case but there really isn't that much "fabricating" you need to do. I'm pretty mechanically challenged and I added the OEM LinQ base/rack (I don't know what it's called) and a Shad 58X top case. From start to finish, it probably took me an hour in a makeshift garage. You only have to drill (4) small holes in the LinQ thing and bolt it all together. (Plus you have to cut out a 3" hole in the middle so you can get to the circular locking thing.)
I have about $700 in my top case setup. Even at todays OEM top case price, I still have an extra grand for gas.