Monkeyfrog, I noted in an earlier post that the Komex contract will cause a fivefold increase in in total US exports of aggregates, sand & gravel. That was based on the stated contract price, but the declared value for Customs purposes should be FOB Port of Exit. So, we can make a few assumptions about freight costs and conclude that we are merely doubling the US exports of this commodity class.
The PR does say it is for export, and the price, at $44/metric ton ($39.92 per ton) appears to have a lot of shipping cost built into it. Assume an average selling price per short ton of aggregate is about $10 net of delivery costs, then make some more assumptions about how it will be transported. Say, by train to port (which port?), then by ship to wherever...