Wikipedia has a pretty decent overview of the concept, honestly.Can you offer an English source on "Wergeld"? I'd be curious to know when and where it evolved. I'd be particularly interested in the extent to which its introduction was more a function of Roman influence than some organic development.
Ancient Germanic Law
The key differences between Hebrew/Judaic Law & the Germanic is in how the debt is repaid, which makes sense. If memory serves(I am just waking up, if I'm wrong call me out) there was not much in the way of liquid wealth in Judaic society. It was nigh-all in animals, slaves, grain, clothing and such. Therefore a 'Wergeld' system simply wouldn't work, it is after all very difficult to decide the price of a man in goats or in fabric.
On the flip side, liquid wealth was extremely common in Germanic societies. They were traders & merchants first and foremost, after all.