The analyst firm said in a 'teardown report' that the added cost of the device's components came in at $265.83. The 4GB model costs $24 less to manufacture, but retails at $100 below the price of the $599 8GB model.
The cost figure represents the so-called 'bill of materials' and does not account for development, distribution and marketing.
The Flash memory module comes out as the most expensive component, costing $48 for the 8GB and $24 for the 4GB.
Both are supplied by Samsung, which also supplies the phone's Arm Risc processor at an estimated $14.25, as well as a $14 1GB SDRam memory module.
The touch-screen module for the display ranks as the second most expensive component at $27. It is manufactured by Balda of Germany and its Chinese partner TPK Holding.
ISuppli projects continued strong iPhone sales, with consumers snapping up 4.5 million units this year and reaching more than 30 million by 2011.
The iPhone's profit margins are similar to those that Apple makes on its iPod media players. But not all of the company's products are this profitable.
ISuppli has previously estimated the Apple TV at a 20.7 per cent profit margin, suggesting that Apple is putting the expansion of its market share ahead of profitability in this case.
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