I can not see much iron being sold by the Norse because they were iron poor. Their main source of iron was bog iron and you don't get that in great quantities.
While the Indians do not get iron in any quantities.
On conquest, if you look at OTL the Spanish very nearly got defeated by the Aztecs. As the Norse do not have the technological edge that the Spanish had so are mosty lightly to be stuffed if they try invading. Raids for gold and silver would be better propositions.
Norse iron is practically usable in ways that Mesoamerican gold and silver are not, and Norse, and their trade partners across Atlantic, value silver and gold in ways that they do not value jade or quetzal feathers. The Indian rulers can trade quite some silver and gold for iron.
Mind you, the Norse CAN invade. There would be no Aztec empire till mid-15th century. Since OTL, Toltec Empire fell in 12th century, the Norse, after sounding out the region by trade, might enter into the fray as raiders, or as allies or mercenaries for Tollan´s foes.
Or how about an ATL where Tollan never falls thanks to Varangian Guard hired by Toltec kings?
Ditto about Yucatan. Would Varangians fight for Hunac Ceel to found Mayapan, or to defend Chichen Itza? Or on both sides?