Once you have exhausted all other channels, then certainly do post. State clearly whether or not the price includes shipping, and if it does, be sure to allow yourself a reasonable amount to cover the cost. Check with your carrier before shipping. Don't advertise equipment that you cannot ship within a reasonable amount of time. Once you have made a deal, state clearly your intentions and follow through on them.
Nothing angers a buyer more than delays and excuses.
Don't be offended if the buyer wants to take steps to protect his position, since he probably doesn't know you. Most readers of this forum are basically honest and want to maintain their net-image, but the few bad apples should encourage you to only deal with honest, reputable people and to reasonably protect your position in any transaction. They are not a party to the transaction, and so they don't care if the buyer gives you a bad check. Check with your carrier for exact COD options and policies. If you choose this option, make sure the buyer knows up front so that he can make the necessary arrangements.