What is your purpose, trying to arb some issuer that you have access to that you can trade with, or are you trying to price and quote them yourself? Knock-ins can be priced from knock-outs and vice-versa. For example, the combination of a down-and-out call and a down-and-in call creates a standard European call, so the value of a down-and-in can be obtained by subtracting the value of a down-and-out from the value of a standard European call. However calculating the risk neutral probability is somewhat more complicated, so my question before pointing you to some material or even try to expand it with you is... Answer honestly how comfortable are you with Ito's calculus and applying it to multiple Brownian processes with correlation? I make use of these instruments from time to time as a hedge instrument when I have a large short position in the options and don't want to hedge only with the underlying. Even-though the hedge is not complete once they have been knocked out, but I somehow manage to tell myself that if the price have fallen so much that it has knocked out my hedge then the need to hedge against high prices diminishes...