What is the "Grid Billing Type" in the pricing calculator excel sheet, and how is it used?

What Is Grid Billing Type?
The Grid billing type will not reduce the number of cells in the grid that need to have a price entered in them. Instead it is a way to have a calculator parameter refer to items in the Grid area as part of the price calculation. 

"Grid" billing type in pricing calculators: A calcparam with  billtype "grid" causes whatever the grid lookup value was to be multiplied  by whatever the formula is. This is useful when you want to use the grid  to lookup a price per set, and then multiply by the number of sets. The  Cost_Per_Billing_Unit column is IGNORED for billtype grid, so leave it  zero.  Also: there is nothing to prevent using the grid billtype on  multiple calcparms, but doing so will probably give unwanted results.