I am not sure about finances, but the phrase sounds like from Shakespeare's "Hamlet". "To thine own self be true" means stay true to yourself. Hope, it helps.

It means that you should not act in a way contrary to your true character. A woman that dates a man for his money, when she really does not like him, is probably not being true to herself. A man that works at a job he hates because of the money is not being true to himself. These people may have convinced themselves that what they are doing is right, but, in effect, they are lying themselves - they are not being true to themselves.

To thine own self be true. And it must follow As night the day, Thou canst not then be false to any man. You cannot be truthful about other people until you have learned to be truthful about yourself. If you are leading a life of pretense and many masks, then you will ultimately project those masks onto everyone around you, thus being false to other people.

This is oooolllldddddEnglish...."thine" means you. Basically, it means, "Don't lie to yourself."