Hello, I use Excel as well. It's a great way to keep track of the costs of each item you purchase. I go by cost of goods and add all supplies for the job together. For the main material, say the vinyl I use a cost per square inch. Add up all components and X's it by a percentage of margin I want to make on the projects. In Excel you can then take the calculation and X's it by the number of units ordered. If you know Excel it's a wonderful time saver. You can play around with your margin dollars to feel comfortable with your offering. This way when someone does request a quote or offer up a dollar amount you have a place to go to review the offer. If you want to make more or make less at least you know where your costs are so your not loosing money. You need to track your inventory and material costs per job otherwise your shooting in the wind.