Adventures through Trechara
Shopkeepers often don’t sell you the price they sell to everyone else. The list of what it cost to buy an item is listed here:
Hated by Shopkeeper: Won’t sell or +100%(double) price
No Opinion: +10%
Liked: Base price
Favored Customer: -10%
If you shop more at a specific store you will be have lower prices, if you’re rude to the shopkeeper or his friends, you will have higher prices.
The first time you enter the store the player and the shopkeeper will roll opposing diplomacy versus sense motive checks to find the shopkeepers disposition. If the rolls are within 4 of each other then the shopkeeper has no Opinion. If yours is between 5-9 higher, then you become liked. If yours is between 5-9 lower, then you become disliked. If there is a more than ten difference than you either become Hated or a favored customer.