Karma Based Character Creation, Some math Options

[Xarei]

I just picked up Runner's Companion and was really pleased to see Karma based character gen in it, I've often played with 3rd party Karmagen rules in the earlier editions and I was happy to see it "officially" this time around.
However, when I tried to make a character I was struck by how odd the math was...

So looking at the totals: 400 BP = 750 Karma or 1 BP = 1.875 Karma

Looking at flat costed stuff like nuyen or qualities, 1BP = 2 Karma, this seems to make sense a tiny rounding difference is small price to pay not to have to get out my calculator to buy gear.

But looking at attributes:
Buying an Attribute up costs 10 BP per level, 40 BP for Strength 5 for example

Buying an Attribute up costs New level * 3 karma, 42 karma for Strength 5
(Start at 1, 6k for 2, 9k for 3, 12k for 4, 15k for 5)

Which is 1BP = 1.05 Karma

I picked 5 because it is the highest ratio of Karma to BP, for attribute values 2-4 it costs less karma than BP and I wasn't certain if you were still supposed to pay a 'tax' for maxing an attribute.




So, did I miss some errata? Like if attributes were New Value * 5 it would be closer to working out.
If not, and that is how it's intended, has anyone run a game with Karamgen? How does the favoring of attributes (and to a lesser extent skills) over Qualities, nuyen and contacts effect the game?