It may not be an unnamed source or an expert on the matter, but the continuously lowering of the current iPhone models' price is as much a sign as any.

A spokesperson for Wal-Mart told CNET that the retailer further reduced the price of their iPhone 5C and 5S. With a two-year contract under Verizon, AT&T, Sprint and U.S. Cellular, the retailer is selling the 5C for $0.97 and the 5S for $79. Yes, that is 97 cents for the iPhone 5C.

Wal-Mart is just one of many retailers that are dramatically lowering the price of the current iPhone, an indicator they are trying to empty their shelves for the arrival of the latest and greatest. RadioShack and Best Buy are among other major retailers to lower the price of the iPhone 5S/5C.

Now several insiders are saying Apple will unveil the 4.7-inch iPhone 6 on Tuesday, Sept. 9 and then release the device possibly Sept. 19 or 26. However, some sources are unsure when to expect to see the 5.5-inch "iPhablet."

Ming-Chi Kuo, a trusted source for Apple-related rumors, told Apple Insider more than a month ago that the company was having production issues with the larger handset could push its release into 2015. When Apple releases its new iPhone, the previous model typically gets a $100 discount and the one before that is usually reduced to free with a two-year contract.

Currently the iPhone 6's features and specifications are purely speculation and rumor, but the handset is expected to have a reversible USB cable, a 13-megapixel camera and various software improvements. One of the more mysterious rumors is whether or not the iPhone 6 will have sapphire crystal glass.

Some reports have said Apple has not produced enough to use on all the units it plans to ship, while others are more hopeful. The material is usually used for the camera lens and Touch ID fingerprint scanner since it is super tough.