The Potential inside everyone is infinite and no one is in any way cheap. The difference is all that is imbibed during the process of growing up. Human beings do things as per their understanding and the acts of dishonesty are mere the result of lesser understanding. Culture teaches a person a belief system that he finds a way to justify dishonesty and he does that assuming it to be correct.
The way out of the situation is to understand more. Go into the mindset of the dishonest person and identify the baggage of thoughts, culture, and upbringing he carries and why he resorted to dishonesty. Clarity of thought is what human beings are built with and they need to attain that status for every why and how that their imagination throws up.