Suppose the name of column A, the price of column B, the quantity of column C and the total price of column D, and columns F and G are price lists.
Enter the formula in cell B2:
=vlookup(a2，$F$2:$G$ 10，2，0)
Enter the formula in cell D2:
=B2*C2
Then select the "B2:D2" cell and drag the fill handle to fill it down.
The attachment is an xls file and can be downloaded.