Another note about ECU tunes:
Their value depends on how heavily you mod your engine!

If you're just adding a Code3 or 178mm pulley and a cold air intake, an ECU tune is not worth the money.

But once you start greatly modifying the amount of air your engine can draw, you'll get beyond what the stock programming can adjust for, and potentially blow your motor.

So draw a line after the cold air intake and Code3 or 178mm pulley. If you don't go any further, don't bother with the tune. If you add intake manifolds, polished Y-pipe, etc. etc. etc. Then definitely get the tune. If you go larger on the pulley: get the tune. You get the idea.