Qualcomm ICs in the phone are: an apps processor/baseband ($38), RF ($18), WLAN & front end ($5), and power management ($8).
Out of a total $201 BOM, Qualcomm takes $69.
The other big items are memory - 32GB of flash and 2GB of low power DRAM costing $36.50, screen ($27.00), cameras ($20.50),UI and sensors ($11.50) and the mechanical/electro-mechanical component costing $28.
The retail price of $650 looks like the sort of mark-up you expect to get on a bottle of wine in a restaurant which Amazon would doubtless put down to R&D, licensing, software development etc.
It still seems a hefty margin - and out of keeping with Amazon's strategy on the Kindle which was to sell it at cost price to get share.
As it is, this looks like a me-too phone, costing the same as any as other top-range phone and no prettier.