Over the four months (April-July), Munster tracked various prices in the resale market. He found that the iPhone 4 actually jumped in value by 10.3 percent, while the iPhone 5 declined 3.75% and the iPhone 4S dropped 11.85%. Samsung saw the Galaxy S3 lose 27.3% of its value while the Galaxy Note 2 dropped 35.5%.
Munster's data does not provide the entire picture of the resale market since its based solely on eBay sales in the US. There is also some data from China:
The situation was similar in China. Since the start of April, the iPhone 5 dropped 7.2 percent in resale value, the iPhone 4S fell by 14.3 percent, and the iPhone 4 grew by 1.4 percent. The value of Samsung's Galaxy S4 fell by 14.3 percent, the S3 by 24.1 percent, and the Note 2 by 23.6 percent.
Any rapid drop in iPhone resale prices usually means consumers waiting for a new model or jumping ship over to another vendor. However this data is a sign that customers are still enjoying their iPhones, in no rush for a 5S upgrade.