And if you use the "Unit Selection Cost UI" mod it will show the price of the selected unit, so you can easily compare the mass price of the unit to the mass killed.
Whether a unit pays for itself though is a much more complicated question, including:
-Who gets the reclaim when the unit ultimately dies?
-how long ago did you pay for it? If you built a unit 10 minutes ago, it was idle for 10 minutes, and then it gets 3 kills for 300% mass return on investment, that didn't really pay for itself.
-energy cost, which matters especially for air units
-what else could it have been? An ilshavoh with 200% payback on value vs. cost is nice, but if it could have been a mobile flak with 500% payback on value vs. cost, then maybe it wasn't the ideal choice
-did the unit help you to secure a reclaim field? Then it might pay for itself 10x over even if it doesn't have much mass killed
So it's not worth adding a new indicator
