first off, is it worth it?

and second if i buy a used one can i send it off and get it re-tuned for what i have on my car?

 

If it's unlocked you can just give it to a tuner.. if it's married to another car, you'll have to pay 150 or so, to send it to SCT to have it unlocked...

but imo, it's not worth it. Just get a Xcal2, or 3 and that's all you probably need

 

+1 ^^^ Xcal 2 or 3 the way to go...