Adventurers, being commoners, are more likely to get screwed on transactions. Unlike knights, they basically have no recourse against blacksmiths who decide to overcharge, and unlike traders don't have much haggling ability. Also they pay taxes, or perhaps the price of the gear is hiked up to include taxes. So their gold may not go as far as you might otherwise think.
Blacksmiths? Blacksmiths make horse shoes and pick axes. Armourers is a skill and trade separate from blacksmiths. Blacksmiths are likley to be commoners as well, and thus subject to the lords justice. Most lords would hold court were such grievances could be resolved. Armourers capable of making good quality armour, I have no idea where they would fit in. In later periods they are probably part of the merchant caste.
