RadioShack is having a $50 discount sale on the iPhone 4 and iPhone 4S on all carriers until June 30. The deal is valid at every RadioShack location and can combine with trade-ins through the company’s Trade and Save program. Target is also offering a similar $50 price cut on the iOS smartphones. That means the 8GB iPhone 4 is $49, and the 16GB iPhone 4S is $149, etc., at both retail stores.