Identify the real cost of a FIFO item

We use FIFO and item costs can vary depending on when we buy them, I need to be able to calculate the cost of an item based on the cost tier. I looked on ARINVOICEHISTORYDETAIL and it appears this table pulls the cost from Std. Cost and not the tier it pulled from.

From what I can tell, the tier isn't calculated until the batch is run. Is there a way to tell the true cost (from the item's cost tier) was actually used?

Thanks!