If you’ve been debating buying an iPhone in the hopes that the price would drop, you may be in luck. That is, if you’re willing to give a refurbished iPhone 3GS a try. At $9 (with agreement to a two-year contract), AT&T is giving its customers the opportunity to pick up an iPhone at a lower price than ever before.

So, is it a good deal? This depends on what exactly your needs are. If you plan to use apps that really don’t depend on the front facing camera or other perks of the iPhone 4, and you don’t mind using a phone that will be two generations old within months, this might be a terrific deal.

When compared to the iPhone 4 (currently priced starting at $199 for new / $99 refurbished), the 3GS has lower display and camera resolutions, no front-facing camera, and a lack of Flash. The iPhone 4 also features a slightly faster A4 processor, LED Flash, dual-mic noise suppression, and a three-axis gyroscope. Whether or not these added features are actually deal breakers depends entirely on what you are looking for in the device.

Refurbished iPhones carry the same warranty as brand new products and include a new outer body so you don’t have to worry about scratches on the screen or other physical flaws ruining your experience. These phones operate exactly as they would if they had never been used before, and are often the result of an open box and immediate return. Warranty service is still provided by Apple just as if you had purchased an iPhone 4 brand new directly from the Apple Store. In the vast majority of cases, you would never know you’re using a refurbished unit except for the extra cash still in your pocket after purchase.

For the majority of regular users, the speed and capability of the iPhone 3GS is just fine. Texting, browsing, compatibility with iOS 4, and access to many of the iTunes App Store’s most popular apps are areas in which the 3GS is fully capable. After all, the iPhone 3GS was top of the line only one year ago.