A data point......about a year ago I received $11,500 in trade-in for a 2015 FFE with 38,500 miles. And before somebody runs off and says I got a higher trade-in value because I got screwed on my purchase price, this was a trade-in for a vehicle where the manufacturer doesn't negotiate on price.
GONE - 2015 FFE, Magnetic with leather interior, debadged & tinted
38,500 miles (since May 2015), average 246 Wh/mile
REPLACED WITH - 2018 Tesla Model3, LR RWD, Obsidian Black
20,000 miles (since Nov 2018), average 235 Wh/mile