I like the thought of that, KingAlan
Both ides are good, ether speed up production of a ship class or decrease ships cost of a class.
As Monroe mentioned it would probably make more sense if it speed up production time.
The hard part then is to set the line... should 10 light factories speed up production with 1 tick or more? Or are 20 light factories need to speed up a tick for the "light" ship class.
You could set it up like this then... or are more factories needed...
10 Light factories - speed up "light" class ships by 1 tick
20 Light factories - speed up "light" class ships by 2 tick
30 Light factories - speed up "light" class ships by 3 tick
etc. and so for the other classes..