Amy,
Well, how bad do you need the money; how many trees are we talking about; are the trees high quality or low quality?
All of these are factors concerning your moral dilemma. Therefore, call a professional consulting forester and have him/her appraise the trees for you. The consultant will advise you as to whether or not the trees are marketable (as many yard trees are not marketable) and how much they would bring at sale.
Your consultant's advice will undoubtedly answer that difficult decision whether, "to cut, or not to cut".
Good luck!