https://9to5mac.com/2018/07/23/iphone-x-resale-value/
Liquidation specialist B-Stock says that high demand is seeing used models sell for an average of 85% of the original price.
Even bulk purchasers, such as companies buying returns from retailers, are paying around 75% of retail.
"The iPhone 6, 6s, 7, and 8 all achieved roughly 65% of retail value six months after launch across our network of mobile marketplaces," says B-Stock, putting the X in a truly exclusive place. It seems that folks who got the iPhone X have been seeing it depreciate much less than their monthly payments, after all.