Does costing capture revision specific costs of items?

No.

Costing provides costs based on effectivity dates. When Product Development retrieves costs from Costing for a leaf item, it will use that cost for all revisions of the item, regardless of the item's effectivity date. If a leaf item has a cost of $15 from Costing, the amount will carry to any future revisions of the same item - as long as it's still a leaf item. If the cost of the item changes in Costing to $20, the next rollup in Product Development displays the cost of that leaf item as $20, which would carry to future revisions of the item.