The average price for used Apple iPhone 6 16GB today is $30.
A new one costs $80.
This page displays the history of price changes for the entire time of monitoring this device.
The average price means that this used device is bought for this money in most cases. Hundreds of listings are analyzed to calculate this value every day.
If the information about the price is helpful to you, then share the link to this site with your friends, please :)