Observing the BOM is interesting. Many of us in the assembly business are disappointed that this innovative product is assembled in the Far East. However, assembly cost savings may not be the only reason for Far East assembly. If one looks at the bill of material, almost all of it comes from the Far East, the memory, the display, the applications processor, etc.
iSuppli estimates the assembly cost as $10 dollars. This amount strikes me as too low. A good rule of thumb is that assembly cost is at least $0.01 per I/O assembled. So if the all of the PCBs have more than 1000 I/O the assembled cost is likely higher. It is hard to estimate the I/O, but there are 100s of passives alone and typically the BGAs will have high I/O counts. I just noticed that I don't see passives on the BOM. Typically they are about 90% by part count of the electrical components.
They are inexpensive, but with their high numbers, their price can add up.
Solder paste is typically about 0.05% of assembled cost or about $0.20. When one considers the importance of good solder joints, it always pays to use the best solder paste available.
The image is from iSuppi's article.