The reason I can come up with this conclusion is the fact the price is set at $499 and the 80GB model costs $448 according to iSuppli.
Using resources like NewEgg.com I compared the prices of a 80GB HDD and a 160HDD and found at most there is a $10 difference in cost. Add in Uncharted: Drake's Fortune's disc cost at about $1* or less and Pain's price of $9.99 than adding isuppli's 80GB model cost I can estimate the cost of the 160G model costing Sony about $469.
So doing quick math $499 - $469 = $30.
So Sony makes roughly $30 profit off of every 160GB model sold.
* - estimating replication costs due to the game making a profit.










