When will iPhone 4 prices start dropping?

I have the Samsung Galaxy S3, however the screen keeps cracking and would now like to try the Apple iPhone for the first time. I'm due for an upgrade next year, so I decided I would go for one of the older/cheaper models to give it a try, then decide next year which direction I want to go in. I think I'm going to try and land an iPhone 4.

With the recent announcement of the 5s and 5c, I expect the prices to start dropping for the iPhone 4 (ebay/amazon). When do you think I should pull the trigger? Also, does anyone think I should just get the 4s?

Your upgrade isn't until next year, so decide then.

The iPhone 4 cost 1 dollar with a 2 year contract from atnt

The iPhone 4 was discontinued on September 10, 2013.
Some stores might have a few left.