Item Costing Methods - Serialized Items

I am reviewing the standard NetSuite options for Item Costing.

The options listed don't seem to mention Serialized Items - please can you confirm how Serialized Item cost prices are calculated on sales?

I can see that on a Purchase Order for a Serialized Item, the serial numbers are recorded when the items are received. Does this mean that the actual cost price (from the PO) is recorded against that serial numbered item? Would this then be used on the Sales Order as the cost price when that serial numbered item is sold?

Our problem is that we have some 'generic' Item Codes that are used to process orders for many custom/bespoke items (and the cost prices for these can vary greatly). We need an accurate way to record the cost price of the item and apply that cost to the sale for that specific item.