It shouldn't come to be any surprise that Apple decided to keep its prices steady for the upcoming iPhone 4 – which means that people will need to save at least $200 to get in with one. Naturally they'll have to scrounge on whatever money they can find if they're strapped already for cash, but stopping by your local RadioShack store may prove to be beneficial if you're still sporting an older iPhone. The retailer has announced one attractive offer for those who currently own an iPhone and plan to move up to the newer model when June 24th comes around. Between June 24th and July 25th, customers can receive store-credit gift cards as long as their iPhone is in good condition – $100 for the iPhone 3G and $200 for either of the iPhone 3GS models. Some might wonder if their handset will garner a “good condition” rating – apparently the retailer will accept it as long as there is no evidence of cracks or the display or water damage. So if you're willing to part ways with your beloved handset for its latest incarnation, RadioShack may be one of those stores you'll be paying a visit come launch day.