The last step in negotiating your transaction will be the invoice. It is imperative that you state the terms of the sale in your invoice or you could be out some potentially good money if the client thinks they can keep using your photo because you did not spell out the terms.
For this image I negotiated a two month usage for local magazines with a small circulation. The book price was $400 but because I have extensive Photoshop work on this image I was able to get another $175 for its production value. My invoice stated the following: The content you are trying to access is only available to members. Sorry.