Induced drag goes down as speed goes up, but it will still be the predominant form of drag on the aircraft at speeds below about 200 mph. (That REALLY depends on the value of C_Dp for your particular craft). In other words, reducing it will get you the greatest gains in drag reduction.
Ken,
I am pretty sure that this is incorrect. Why do you think that induced drag is the predominant drag component below 200 mph?
banktoturn