In my experience mods don't increase the value of the vehicle being sold. That said you'll never sell a vehicle for what you put into it (well you might have the opportunity haha), factor your maintenance after your done adding up mods....still if your looking for a chance to do something different or start new then this could be a good opportunity. I bought my 01 vx with 57,000miles last year November for $13,000 and now with 73,000miles wouldn't sell for less then $15,000 because I need a vehicle to drive everyday and getting anything less wouldn't be worth trying to find a new dd.....unless of course they offered me 12 to trade on an evo.....then id think hard.