[SOLVED] Post a value in a cell based off the value of an index cell?

I know this is a simply answer but I'm not sure how to set it up, though I'm pretty sure it will be using a VLOOKUP formula. Basically I have a sheet of data that consists of sales, each row containing one sku and the associated costs, etc. that accompany the sale. So basically I am just trying to calculate profit in a given time frame but I need to plug in cost of goods into one of the columns. The cost of each sku I have in another spreadsheet. In the example spreadsheet, how would I get Column K on sheet1 to auto-populate based off the corresponding values in Column B of sheet 2 when Columns B in sheet1 and Column A in sheet 2 match? Example_Book1.xlsx