This calculation uses the list price from (digkey, mouser and newark distributors) per 1000 chips for every specific functions. For example the average price of a standard two channel multiprotocol serial linedriver [460kbps] is 80 cent per 1000. A high performance linedriver capable of 20Mbit cost on average 2,5 euro. So the base price of a linedriver is 80 cent and 8,5 cent extra for every 1Mbit of speed added.