Surprised no-ones opted for dura-ace Di2!
That will be a serious contention with my next bike, but it won't be for a long time yet.
My CAAD 10 cost me £2800 including an upgrade at the point of purchase. It then got 'blinged' to in excess of £3k

Although I have scaled it back now to make the bike more durable and ergo more usable in the real world
Can I warrant spending anymore than this on a bike? No.
Do I do it justice? No.
Does it make me go any faster/farther/longer/harder? No.
Will I spend this much in the future? Hell yes. (if and when I can but I suspect we'll be on third of fourth generation Di2 by then).