Manufacure Costs for BGA - QFP - QFN at Seeed

Hi All

I am working on some open source hardware (an ARM board to run linux with ethernet and USB) that I want to sell and manufacture through Seeed. I estimate the BOM will be around $30 but manufacturing is what might be a problem.

Is Seeed able to do BGA? I have 2 BGA IC’s (~300 and 84 pin, 0.8mm pitch). What is the cost difference to manufacture BGA veresus 0.4mm or 0.5mm TQFP for example?

Is the difference between QFP and QFN significant?