"Really hate to sell this but I desperately need CASH for _____ (fill in the blank with horrible tragedy). Also would consider trade for ______ (fill in the blank with any number of non unicorn guns)."
Those are great....I do however question the motivation behind outting yourself in that manner. Am I somehow more likely to buy the rifle from you because you are getting a divorce? Or will I be more quick to make an offer if I know you have a surprise bill? I understand that life happens and folks need money but either we have some of the most unlucky members in the world, or folks are attempting to take a lot of advantage.
