I always wonder about things like this. I mean "There’s the hard drive from Seagate ($37),". Where did this $37 come from, cost price of a general unit?
Sony are a large hardware manufacturer with very good relations and partnerships with companies. Would surely do a deal saying "We are going to be putting your HD in millions of consoles." and then negotiate a price based on amount of units. So $37 might be $30.
Hmm, pie.