Character Generation - Best Bang for the Buck, 5th ed. Options

[yesferatu]

So I am making a 5th ed. shaman and I'm trying to figure which priorities are the most efficient.
For example, the Attribute priority provides 24 points. Buying up attributes later will cost new rating X5, so getting those as high as possible first saves a ton of karma.
Magic as a B priority is only 2 Magic points below priority A as well as 2 skill points and 3 spells. I think you could make most of that up with other skills or build karma.
Is it more expensive to buy skills up later - since there are a lot of them - or is it more efficient to take them as a higher priority?

So, what do you think? Are certain priorities worth more than others?
Has anyone done the math?