Other than Cobb, is there anyway to sell a tune if you ever decided to go to a different tuner or tuning device?

My guess is no.....

 

Dont think anyone else have a resale value (maybe the durametric cable holds a negligible value).

 

GIAC will offer upgrade pricing for cars with previous tunes... typically.... but maybe not on all cases. Evo does the same, upgrade pricing for previous tunes.

 

Still you cant "sell" the tune like the AP.

 

The durametric is useless as well. You could make it "sellable" if you can "hack" the unit. But its not worth it. Programmers do that so you cant buy it from them and tehn sell it at 50% off.
Now if you sent the code to someone east and south of you I am certain they would figure it out and make you a pretty penny. Probably drop the price of tunes to a more BMW/MB price range
Also if you run across any andriod programmers hook me up as i have a great idea.