Board Thread:Wiki discussions and announcements/@comment-1990160-20140521040036/@comment-1330314-20140523162637

Armor and magic resist do not have diminishing returns: one point of armor will increase your health by 1% against physical damage, regardless of how much armor you already have stacked, and the same goes for magic resist and magic damage. The effect you are mentioning does not exist.

Similarly, as has been said multiple times before, gold value does not concern itself with the effectiveness of an item relative to a champion. This includes the champion's stats, and whatever they may choose to build along with the item you're evaluating. The gold efficiency of an item may certainly reflect its interaction with other items ( is only barely efficient because it increases the efficiency of other AP items, looks gold inefficient because its power comes from its Spellblade effect, which is not only very strong but also scales with other AP items), but it should not be influenced itself by the potential addition of other items.

The dynamic data you're trying to find is a measure of effectiveness of an item build, which is actually fairly unrelated to gold value. Since there is no component for effectiveness, you wouldn't have a precise gold value to work with for anything, but the major problem would be that you'd have to account for a whole lot of variables. Unlike gold value, there is no way to quantify these variables in terms of gold, and these gaps would be harmful to your system in general. Gold value, on the other hand, can handle gaps in the value of certain stats, because it does not claim to measure every aspect of an item, just the stats it knows. What is unknown is marked as such, and if the item is gold inefficient it is accounted for as part of the item's uncountable bonuses.