Board Thread:Wiki discussions and announcements/@comment-3308937-20150122092301/@comment-5606883-20150126132230

I think that, while its true that Cost Efficiency isn't exactly "helpful" in the heat of a LoL battle, it's a cool feature to have. Kinda like a "The More You Know" thing. Usually when an item is more cost efficient than another, the other item has strengths that the first one didn't or a specific champion synergizes with it more effectively than another so its not a very good way to measure how good an item is.

I would vote to keep the feature just because it's cool.