What will be the cost of the final product when I do return and the the cost of the componenet has b

I have item B is a BOM

The BOM B is composed of Item X (qty 1) with cost 10 and Item Y (qty 2) with cost 20 USD. Currently B cost is zero

Create a wip job number J200 for the item B with qty 3 to complete

complete the job

close the job

Cost relieved in Job : 150
Assembly Cost is 150

Currently Cost incurred =150
                Cost relieved =150
                Net activity = 0

X cost = 10
Y cost = 20
B cost = 50

now the cost of Y has been changed to 25

Open the Job above J200

do a complete return of item B the BOM for 1 Qty

close the job J200

What will be the new cost of B?