Conditional testing without lengthy nested IF functions

Many a times writing nested IF() statements become cumbersome, lengthy and highly prone to errors. 

In worksheet named “Question”, one would like to avoid using spare columns for computation of landed value for the three product sources (“CKD”, “LMP”, “IMP”).  While one can use a nested IF() statement, it would be unmanageable because of the length of the formula.

One can have the computations for “CKD”, “IMP” and “LMP” reside in a table and then refer to that table within formulas?

You may refer to my solution in this workbook.

You may refer to another example in this workbook.