Apple is tight-lipped on its upcoming flagship iPhone 8 and two other handsets -- iPhone 7S and iPhone 7S Plus – but almost every detail, including their key specifications and pricing have been leaked over the last few months. Now, it has emerged that the iPhone 8 could be Apple's most expensive device so far.

The Cupertino giant is expected to unveil iPhone 8, iPhone 7S and iPhone 7S Plus in September before releasing into the market a few weeks later.

Goldman Sachs has predicted that the iPhone 8 will come with a price tag of $999 (£775), iPhone 7S at $649 (£503), and iPhone 7S Plus at $769 (£596), according to the firm's note to its clients obtained by Business Insider. It said the screen itself could cost $35, $20 on 3D sensing, and $16 to $29 on RAM. 

"We expect the iPhone 8 to have 128GB and 256GB models priced at $999 and $1,099, respectively," said analyst Simona Jankowski and her team in a note.

iPhone 8 Copper Gold leaked render
Leaked renders of iPhone 8 Copper Gold confirm notch design, dual-rear cameraBenjamin Geskin via Twitter

Will you buy iPhone 8 for this price? Well, it would be $130 (£100) more than the most expensive iPhone but it will also come with superior features.

Apple is expected to announce three variants of iPhone – iPhone 7s with 4.7-inch screen, iPhone 7s Plus with 5.5-inch screen, and iPhone 8 with a 5.8-inch OLED (organic light-emitting diode) screen.

All the handsets are expected to share several features like bezel-less display, no home button, A11 chipset, an iOS 11 operating system, 3D depth-sensing front camera, wireless charger, and new fingerprint ID solution.

The iPhone 8 is expected to come in 128GB and 256GB models internal storage.