Sourcing parts found on FriendlyARM boards

I've been working on a project based on the AllWinner A64 with similar
specs to something like a NanoPi Neo Air and I had question about sourcing
parts/assembly. How is FriendlyARM able to purchase Allwinner SOCs and
'Samsung' RAM/eMMC at such low cost? Talking to Vendors on Alibaba I can
usually get the total of the core components down to the price of a
complete NanoPi board.

~$5.50 eMMC(KLM8G1GEAC-B001)
~$4.00 SDRAM(K4B4G1646D-BCK0)
~$4.00 SOC/PMU(A64/AXP803)
~$4.00 Radio/PMU(P6212)

Then there's PCB Fab and assembly of a double sided board 6 layer. My
question is where do I look to source these parts and assembly if I'm
looking to do a run of 1500 boards? Is it even possible if I'm located in
the states and not directly in Shenzhen? Will I see better prices if I hire
an agent to shop around for me or is it not worth it if I'm only making
1500 boards initially?

Any help would be great, thanks!

They probably have developed a good relationship with their suppliers, ie
buy their bits directly from them and at much higher volume.

1500 is pretty low quantity to hope for good price breaks.  We had an agent
in China and apparently it was good value, but we were buying millions of
dollars worth of parts through them.

Have you priced 1500 6 layer boards from one of the large Chinese PCB
manufacturers?

I suggest you post this in the "Off topics" forum at avrfreaks.net

There are many low-volume developers/manufacturers on that site.  I am sure
you will get many responses.

I figured it was just a function of volume, but I can't imagine FriendlyARM
is purchasing millions in components. I'l post on avrfreaks now, thanks for
the advice!