[Suicide Junkie]

You start with say, 40%/0% (ECM/Sensor modifiers)

If you spend 20kt for basic components, you can get that up to, say 60%/20%

If you spend 40kt for both basic and advanced, you get up to maybe 50%/30%
(10%/10% MORE, for 10kt more)

And if you spend 60kt for all 3 classes, you could get 55%/35%
(5%/5% more, for 20kt more space)
IE, less of a boost for the second and third addons... diminishing returns, you see?