Answer:
$8,400
Explanation:
The computation of the annual financial advantage (disadvantage) for the company is shown below:
Particulars                     Make                             Buy
Direct material           $53,600 (8,000 units × $6.70)
Direct labor                   $64,800 (8,000 units × $8.10)  
Variable manufacturing overhead $8,800  (8,000 units × $1.10)  
Supervisor's salary	$16,000  (8,000 units × $2)  
Fixed manufacturing overhead	$2,000  
Opportunity cost	$16,000  
Purchase cost                                                                $169,600  (8000 × $21.20)	
Total relevant cost       $161,200                              $169,600
So, Financial (disadvantage) is 
 = $161,200 - $169,600 
= -$8,400
We simply compared the make and buy cost and as we can see that the cost of buying is more than the cost of making so there is a extra cost i.e to be incurred of $8,400 if out side supplier is chosen