Modular Items

What if Riot overhauled the item system, and instead created a series of items for each stat, such as +5/10/15/20 ect. AD items, and let you build items with varying amounts of stat, lets say you wanted to make a bloodthirster, depending on how early you want it, you could have anything from the current BF sword and vamp scepter to something more extreme such as a dorans blade and pickaxe variant, with stats reduced accordingly. instead of an item with fixed stats you could have an item guideline and use any recipe item for that stat in the slot. the premise of this idea came from thinking about how many items have 20% cdr on them, when 10-15% is sometimes more desirable, and having modifiable stats would lead to more gold efficient builds, since you could buy only as much of a stat as you need. Thought?