Purchased Parts 'Material Burden Cost'

We are on Vantage 6.10.541, we are trying to account for our 'burden' cost for 'Purchased Parts'.
This is for parts that will not be included in any Job, these are parts that we 'distribute' , we buy from a Vendor and in turn sell to our Customer.

We have applied a 'Mtl Burden rate' thru Part Maintenance.

But it appears that the 'Stock Status Report' does not include the 'mtl bur cost' for those parts, also, checking 'Profitablity' after invoicing, it again appears that the 'mtl bur cost' is not included for these parts.

Does anyone have experience with this? WHat good is the 'bur rate' and 'mtl bur cost' if it is not used?

Thanks,
Bill J.