As far as the Nexus 5P, I think Google has (rightly) bet that mid range phones are the future and won't make a 5P unless they can keep the price down.
Yeah. That's true. That would be a damn shame though.
Maybe if the iPhone 6c rumors are true, that'll get others to start making premium mid range devices.
Samsung's latest A series are mid rangers and they look pretty premium. But you're right, what will their prices be. Probably not that cheap.