Formula for Sum and month lookup

[John Smucker]

I need a formula that sums up the totals from the Magazine Ads and Bag Stuffers and also finds a month (or months) in the date column, returns the value (or values) from the Total Cost column and adds them to the sum, leaving me with the total cost for the Magazine Ads, Bag Stuffers, and Shows for January.

 

[Sufiyan97]

I need a formula that sums up the totals from the Magazine Ads and Bag Stuffers

in which column they both are located?