INDEX/MATCH with Multiple Conditions

Hi...

Please see attached. I have a client database which is used to calculate how much money is spent per client each year. We have 2000 contacts and we add at least 10 contacts every two weeks.

For our Christmas gifts, we give out dinner certificates to our clients.

Clients with a rating of C,D, or E have a set amount to their certificates... Clients with a rating A or B have open ended certificates... after their outing, the restaurant let's us know how much they spent.

I've created a way for C,D and E to have a set price (please see"event Index" tab)... but A and B are a bit trickier...

I created a separate tab in the database called "Christmas Gifts A & B"... where i was thinking to record the exact amount spent per client with a rating of "a" or "b"...

How do i get the total to appear in the Column BC under "Master Database"?

Any suggestions would be appreciated.