Is Trinity Force too cost effective?
While the components and full item efficiency are relatively normal, what isn't is the insanely low combine cost. And that's mainly a product of it being composed of 3 items. But while the vast majority of items are composed of two tier 2 components, and must make up between 700-1100g with combine cost, Trinity Force gives you stats during that time.
If anything, Sheen and Phage should have their stats and cost reduced, with Trinity having its combine cost increased. Though that's just one suggestion.
I just don't think it's going to be okay to reward Garen for already building the wrong item, just because the item is so much better than the intended one on everyone who builds it.