Starting today, Radio Shack is once again offering a $50 discount on new 16GB iPhone 4 and 8GB iPhone 3GS units, bringing their prices down to $149 and $49, respectively. According to a BGR report, the deal is good for “new and eligible upgrade customers while supplies last.” The retailer is also offering boosted trade-in credit for iPhone 3G and iPhone 3GS units. “Qualifying iPhone 3G and 3G S handsets will have a guaranteed trade-in…
