Diminishing returns is a fictitious construct made up by those who cannot, or do not want to, afford spending more. As long as you choose wisely, you will always get better sound if you spend more. No one can quantify whether something sounds “2X” better. But we know it sounds better.
What I do not like about these speakers is the two crossover points in the most critical midband range. The crossover would have to be very well made and expensive to not have a detrimental affect on sound, and there’s no way that it is a this price point.