Do not try to write your business plan in one sitting. As I mentioned in the beginning, for a traditional brick and mortar business, it could take in excess of 100 hours to compile all of the information needed into a comprehensive but yet understandable document. For online businesses, probably not that long. But your final product should be well thought out, well documented and easily understandable.
Now, in addition, when you know the average number of transactions per customer and you know your average dollar sale per transaction, you can also project how many customers you would need over those 10 years as well. This would tell you everything about what your business would need to do to give you the salary you want. So, wouldn't it be nice to see what a plan like this would look like? Could you do it? It might not be as tough as you might think.