Suggestion for adding BOM and cost estimates to plans

Leprechaun had a good suggestion here for adding Bill of Materials and cost to plans threads.

I think this is a great idea. People buy plans in great part to save money. We can add up the costs of the plans materials, and then compare those costs to the price of a store-bought tool. So we would list the bill of materials, and the total cost of those materials. Then we would list the price of purchasing a similar ready-made tool, and the total savings from making your own tool.