RadioShack announced a limited-time promotion on Friday that offers a $50 discount on Apple’s iPhone 4 or iPhone 3GS. The promotion applies to brand new devices — not refurbished phones — and there are no tricky terms and conditions to be afraid of. Interested parties just need to be eligible for a two-year agreement, and the offer is valid from December 4th through December 11th. Pricing works out like this:

  • iPhone 3GS: $49.99
  • iPhone 4 (16GB): $149.99
  • iPhone 4 (32GB): $249.99

In addition, The Shack has a “Trade & Save” promotion running that allows iPhone 3G and 3GS owners to trade in their devices for a credit of $75 and $125, respectively. This means a 32GB iPhone can can be purchased for $124.99 when trading in a 3GS, and the 16GB iPhone 4 can be had for as little as $24.99. Eligible trade-ins must be in working condition and cannot be unlocked.