Wording of the College Education:
the character can buy Academic Knowledge skills at half price (rounded up) during character creation. After character creation, Academic. Knowledge skill ranks of 3 or higher receive a 1 Karma cost reduction for each rank.
Hard Knocks:
the character can buy Street Knowledge skills at a rate of 2 for 1 during character creation. After character creation, Street Knowledge skill ranks of 3 or higher receive a 1 Karma cost reduction for each rank.
Tech School Education:
the character can buy Professional Knowledge skills at a rate of 2 for 1 during character creation. After character creation, Professional Knowledge skill ranks of 3 or higher receive a 1 Karma cost reduction for each rank.
Since the default character gen method is priority, the quality would have to address the build from a free knowledge points perspective, not just the karma buy perspective. The powers seem to be intended to do the same thing in each case. I interpret this to mean that for three knowledge skill points in character gen, I get six ranks of that knowledge skill (or for two point, I get rank four).
After character gen, the cost of knowledge skill rank 3 and up is reduced by one each.