Inefficiency is a poor argument for large fines in the first place because its inherently unjust (whoever gets caught is largely paying for the wrongdoing of others). We don't give people life sentences for assault because not all murderers are caught, it only passes muster with fines because our poor grasp on statistics makes it seem like the maths works out even though that's completely untrue for the individual who suffers either 0 cost or greatly inflated cost.
Great point. Which is why the victims of crime levy is bullshit.