It’s time to say goodbye to the iPhone 4 for many of us. As such, you should know that your handset is still worth a lot of money on the secondary market.

How much? That depends on the service you use and whether your iPhone is from AT&T or Verizon. Plus, in some cases, there are price differences between the black and white models. Surprisingly, it doesn’t seem to matter whether your iDevice is 16GB or 32GB.

Currently we recommend using one of the following services to sell you handset: Apple, Gazelle, Amazon, or eBay.

Apple

Apple’s Recycling Program allows you to recycle your old iPhone or iPod using a simple-to-use interface. Depending on the price Apple quotes, you could actually get yourself an iPhone 4S at no additional cost.

Gazelle

One of the first “get cash for my iDevice” solutions, Gazelle has been around awhile now and comes highly recommended. Unfortunately, their current pricing for the iPhone 4 is considerably less than those of the other two sites.

Amazon’s Trade-In Store

Amazon offers high prices for the iPhone 4. Unfortunately, the one big drawback here is that you won’t get cash for your trade-in. Rather, you’ll be given an Amazon.com Gift Card.

eBay Instant Sale Via App

The online auction giant, which offers cash for trade-ins, doesn’t seem to care whether your iPhone 4 is black or white. As such, it doesn’t break down prices according to color.

Our advice: Shop around, because the prices quoted change daily.