Average Selling Price _ Now when you calculate your average selling price which is your cost of sales (material + labor) divided by Ƒ_gross profit), you can determine how many customers you would need and then come up with what you think your conversion rate would be for converting leads to customers, you can determine how many leads you would need. Then from this and with the aid of the U.S. Census Bureau and some basic research on your own you can actually have a pretty decent idea of what size your market is and is going to be in the future so you can see if it will support your business plan or not.
In order to create a strong working business plan you need to place reasonable limits on long_term projections. For the time being, focus on short_term objectives and change and modify the plan as you go along. Too many long_term plans become pointless as they extend too far into the future. Don't be too optimistic, instead stick to being realistic. Over optimism will be your downfall in the end and is only setting you up for a fall. When dealing with timelines, sales and profits err on the side of conservatism as this will protect your business in the long_run. Make sure your business plan is written in simple, clear language that can be understood by all in a bid to appeal to a wider audience and keep things clear.