How do you think this should be fixed?
Fixing Mercantile? I guess these are the start:
*Bartering item within the system. Namely, using item to trade rather than money. Work fines in Morrowind and the Fallout Series, if remember correct. Should help level up the skill
*One level up with Mercantile not by selling one by one, but how much quality the item has. Meaning, ya get more experience selling Glass Armor than an Iron Arrow.
*As for quantity, ya get more experience per bundle compare to selling the item one by one.
*Taking a note from Fallout, we can use Mercantile as a way to unlock dialogue to squeeze out more reward from quest giver or barter one way out.
*Bribing should have some influence from this skill
We can do some fixing for the merchant as well:
*Combination of finite money the merchants has and their money reset after a certain amount of day (3-10 days), one has to visit a different merchant if they has to for selling loot
*Money ya give in the transition with a merchant get the amount ya give, like I buy a potion for 500 gp and now eh merchant who sold it got 500 gp
*Monopoly should not simply exist. Have more than one kind of shop per area. Like having 2 weapon shop but one can specialize axe and another by leather armor and etc
*Some shop are better than other and will give more or less. High exquisite shop has a better chance of selling better stuff, but at a higher cost while the pawn shop buys anything ya have but are VERY cheap in quality. Idea from Daggerfall, no less.
We could incorporate a banking system and weighted gold like Daggerfall, but I think I am getting a bit off the line of this topic.