How to handle item master data duplication with BOM

Hi experts,

All my sales items involve production BOM.

Some of these items has different sizes, I want to duplicate the item master data but use the same BOM, so if I need to make a change, I can change in one place only.

Please see example below and tell me if i got it right:

product code "3343"

I create a phantom item and name it "3343-Master" - no inventory, no sales, no buy (tags)

I create a BOM for "3343-Master".

then, i create item master data duplications:

"3343-1"

"3343-2"

"3343-3"

etc

for each of them I create a BOM and put "3343-Master" only.

this should work good for me? any other ideas?

Can you please tell me if I can calculate production costs that way?

Thank you very much,

Omri