The major considerations when pricing an iPhone 4 are the condition of the phone and the memory size. The phone's network affiliation can also affect its price.
The physical condition of the phone is the most important aspect to consider when pricing a used iPhone 4. Scratches, nicks and other signs of damage lower the price of the phone, especially when they occur on the screen. Water damage also lowers the asking price of a used iPhone 4.
Memory size also affects the price of a used iPhone 4, especially when selling to a private buyer. Larger amounts of memory equate to a higher selling price. When selling an iPhone 4 to a company like Amazon or uSell, the amount of memory is less of a consideration according to a 2012 study by tech website Mashable. For instance, Mashable found that Amazon only pays 50 cents more for a 16 GB iPhone than an 8 GB iPhone.
A final consideration when pricing a used iPhone 4 is the device's network affiliation. Mashable found that AT&T phones tend to earn between $10 and $20 more than their Verizon counterparts. This is because AT&T phones can be unlocked for global use, while Verizon phones are limited to use within the United States.