It seems that consumers will have to wait longer for the release of iPhone 6 and 5S as the price of the previous iPhone is still being sold at full price.

iPhone 5 prices for its 16GB, 32GB and 64GB variants remain high based on the listings on online retail stores such as Amazon and eBay. The unlocked 16GB model of the handset still costs around $600, which is the same price of the smartphone since its release late last year.

US carriers such as T-Mobile offers cheaper price for the handset. T-Mobile is taking a different approach toward offering devices for free. Currently, T-Mobile is offering the latest iPhone 5 with an initial price of $99. The additional $100 is spread out over the life of the contract. The network is also offering up to a $99 credit for those users who trade in an existing iPhone purchased from one of its competitors such as Verizon.

That allows T-Mobile customers to also walk out the door with a new iPhone for no money down. It is a given that the plan will be extended to the upcoming iPhone 6, and could end up applying to devices like the Galaxy S4 as well.

Initial reports claimed that iPhone 6 and 5S will be released sometime in June. Others claimed that Apple handsets will be released this summer.

The expensive price of the iPhone 5 may be due to the reports that the release of the next iPhones will be delayed due to a lot of reasons. Analysts claimed that Apple is facing production issues with the inclusion of new features in the device.

In line with the manufacturing issue is the sudden disappearance of two Foxconn executives directly supervising iPhone's production line.

Some of the rumoured features of the next iPhone are Retina or IGZO screen display, A7 quad core chip processor, iOS 7, 128GB internal storage, 13 mega-pixel camera, and longer battery life. The lack of NFC support on the iPhone 5 was one of the biggest criticisms aimed at Apple's smartphone.

The low cost iPhone 5S, on the other hand, is rumoured to sport a plastic casing, 4-inch screen display, dual core processor and 8-megapixel camera.