Now Seems the Perfect Time to Sell Your Older Version iPhone

Now that Apple finally announce the exact date of launch of new versions for the iPhone, delete the old model that seems prudent. For many of you, this is the way forward. Therefore, where you will go far to dismantle the older iPhones to buy a new iPhone 5? Are you fair trade in your old version? Or just make the current iPhone and buy the new iPhone 5 when you can? Both are equally valid,