Its almost never 1mill = 1 bill. You need to look at the skill types that are injected, as some skills cost 500 mill or 1 billion isk, and those should be included in the cost, and very very long skill queued skills are also a bonus, as well as combinations for characters that are specialized in things. But even then, its rarely ever 1:1 ratio. Usually, at best, 1 to 0.9.