Give me 380USD phone which lasts for next 5-8 years, feels premium, is repairable, camera is decent, replaceable battery, OS is just Vanilla Android with atleast 5 years(more years of Software updates would be welcome) of Software Updates and when you can't provide it, make it hackable enough to install Custom ROMs.
It would be nice to be able to pop batteries in and out on the fly, but I suspect that would make it a lot harder to waterproof. I've lost more phones to water damage than I have to battery death.