Guide them through how you are going to solve their problem. Once you've reiterated their pain, show them how you are going to relieve them of that pain. This does not mean that you should start spouting off the tools that you are going to use. Rather, you should be outline the results your client will see when working with you. Show them how you are going to meet their goals and expectations. Explain to them what metrics you will use to determine success. Let them know that you have their best interest in mind and that you know what you are doing. Now, you'll notice that there is no mention of price. That's because price doesn't matter. What truly matters to a prospect is the value that you offer and the relationship that you have built.
Because newsletter templates are available in all variety of lengths and sizes, there is really no limit to the content that you could potentially write. Keep in mind, however, that you should probably keep down your word count to a level that people are comfortable reading. While you may think everything that you are spouting off is fascinating, it's helpful to first sit down and make an outline of what you want your main message to be, or what the major news is that you are trying to share.