We told you a couple weeks back about Apple’s Reuse and Recycle program offering up to $200 in exchange for your iPhone 4. We also reported that the devices were going for even more on eBay and Gazelle. However, with today’s release of the iPhone 4S, it looks like those numbers are quickly starting to decrease.

Gazelle has dropped their estimate down from approximately $250 to less than $200 for a mint 32GB model on AT&T (approximately $170 for Verizon), and NextWorth is still offering up $215 ($162 on Verizon) for the same model in perfect condition, but any cracks or bad scratches will leave you with around $115. Apple’s program still provides a $200 estimate for the same model (estimate courtesy of PowerON), but we expect that price to follow suit with the other services shortly. Of course the 16GB model is going for a lot less, approximately $170 on Gazelle (AT&T), $135 on Verizon (even less on NextWorth).

If you’re planning on trading in your iPhone 4, today is the day to do it, as prices will inevitably keep coming down as the iPhone 4S hits the market. The good news is if you have an iPhone 4 in flawless condition, you might still be able to get enough to purchase a 16GB iPhone 4S on a two-year contract (if you can get your hands on one).