Viking: Battle for Asgard/Merchants

The Blacksmith
You can purchase all three of the runes here, but none of their upgrades.
 * Location: Brighthelm, west side, closest to the beach.
 * Fire Rune: 220G.
 * Ice Rune: 260G.
 * Lightning Rune: 240G.

Shopkeeper Osgood
After freeing the Hillside outpost and talking to the commander there, he'll ask you to retrieve the lost goods to return to Osgood. In doing so, Osgood will be happy to supply the outpost with equipment. Upon total completion of this sidequest, Osgood will sell you items, upgrades, and maps.
 * Location: Brighthelm, west side one elevation level up from the base's floor.
 * Throwing Axe: 5G.
 * Health Potion: 30G.
 * Meal: 50G.
 * Health upgrade: 400?G (name inaccurate).
 * Gold map: 300?G
 * Urn map: 300?G
 * Treasure Chest map: 360?G

Blacksmith
The blacksmith in Galcliff will sell you up to level 2 runes:
 * Locations: First at the landing camp, then near the dining tables in Holdenfort (after it's been captured).
 * Fire Rune (level 2): 400?G.
 * Ice Rune (level 2): 400?G.
 * Lightning Rune (level 2): 400?G.

Shopkeeper

 * Locations: First at the landing camp, then in Holdenfort (after it's been captured).
 * Chieftain Throwing Axe: 8G.

Blacksmith
The blacksmith in Isaholm will sell you up to the maximum level runes (4).
 * Locations: First at the landing camp, then on the north side of Thornvic (after it's been captured).
 * Fire Rune (level 3): 760?G.
 * Ice Rune (level 3): 840?G.
 * Lightning Rune (level 3): 800?G.

Shopkeeper

 * Locations: First at the landing camp, then in Thornvic (after it's been captured).
 * Odin's Throwing Axe: 16G.
 * Flame Potion: 100G
 * Healing Potion: 100?G
 * Gold map: 350?
 * Urn map: 390?
 * Treasure Chest map: 450?