[Defuser]

Some of this depends on who is doing the labor to remove certain parts. For instance, if you are taking your car in to have the stock springs put back on, the cost of labor in most cases would negate any $ you would receive by selling the after market springs.

Springs ~ $250

Labor to remove/replace ~ $200 (reasonable rate)

Selling used springs for over $200? Not gonna happen.

You have to look at each mod individually and decide if it is worth the time/money to remove and replace. Of course if you have done extreme modding (stanced/hella flush etc) that could cause a negative valuation of the vehicle.

From personal experience I have traded in two cars with mild drops (Eibach Pro kit) with no negative hit taken on the valuation. I just left the springs on there.