The strength of this bonus is more about the time saved than the resources, 150w and 87g alone isn’t that much in castle age (50% disc. was an idea for the italians, but they already saved resources on age ups), the real power comes from denying your enemy the micro sooner.
Old italians already had that bonus (and now that come to mind, I’d like that they would reitroduce it for them) but it was substitute with the disc. FS because it wasn’t that helpful alone, for the portos to have it wouldn’t make them on the level of japs, italians or malay, nor it would really help them enough.
EDIT:
I post that suggestion on the discussion for the italians.