Wal-Mart will offer the 8GB and the 16GB versions of the iPhone starting Sunday, according to a statement of a company’s spokesperson on Friday.

In the press release, Wal-Mart stated that it will sell the 8GB iPhone for $197 and the 16GB iPhone for $297. The prices are available with a two-year service agreement with AT&T

However, many people expected that Wal-Mart will offer a more substantial discount, as the retailer is usually asking lower prices for its products. Rumors on the web even said that Wal-Mart would sell the 8GB iPhone for as low as $99.

The mere $197 and $297 price tags are in-line with the ones at Best Buy, which offers the 8GB iPhone 3G for $189 and the 16GB for $289. Currently, Best Buy is the only other official retailer for Apple’s mobile device.

The two versions of the iPhone 3G are available in 2,493 of Wal-Mart’s 3,200 locations, according to a company’s representative. The fact that Apple is selling the iPhone in a broader number of stores is in opposition to the company’s policy to make its product available in its own retail chain and just to a couple of other retailers. At the moment, the iPhone is available in all stores of Apple, AT&T and Best Buy across the U.S. Apple offers the iPhone in 70 other countries through a number of wireless carriers.

A researcher at Piper Jaffray pointed out that Apple’s partnership with Wal-Mart could boost iPhone’s sales figures by more than 10% next year. If the prediction will turn out to be true, Apple might sell enough iPhones to cross the 50 million units mark in 2009.