My view:

1) Someone who obsesses over pennies per gallon is someone who also takes shortcuts with maintenance for the same reason: short term financial concerns.
2) If 20 to 50 cents per gallon is that big of a deal, given that most Crossfire owners are older, I'd ask just what you did in your life that a few cents per gallon is such a big deal to you at this point in your life.
3) The ECU will compensate for low grade fuel, but just watch the numbers, the ECU does not KNOW what fuel you put in, it reacts to knock and retards timing, but it does not magically know what fuel you put in the car. THe idea that you "cann ot do damage" due to the ECU "compensating" outlines clearly that you do not understand how the ECU manages the engine. RUnning cheap gas is the same as running 10W40 conventional oil: if you honestly believe the engineers had no reason to specify a certain product, Dunning-Kruger is alive and well in you.