Base Price
In Oblivion every item has a base price that is listed in the inventory. The prices provided in all of the tables on this website are base prices.
You will generally never be able to buy or sell items for their base price. When interacting with merchants, you need to haggle with them to negotiate the price at which they will agree to buy or sell items. If you are selling an item, you will always receive less than the base price. If you are buying an item, you will always pay more than the base price. You can think of this as the merchant's profit margin. The only exception is once your Mercantile skill reaches 100 (without the help of Fortify Skill effects): you are then able to buy and sell items at their base price. Haggling is governed by your Mercantile skill.
For some items, such as Spells and upgrades for Houses you never see the base prices of the items (i.e., after you have purchased them, you do not see their price listed in your inventory). However, base prices are still defined for each of these items (and are the prices listed at the provided links); these base prices are adjusted by haggling in the same way as all other items in the game.
 Zero-value Items
You will notice items in your inventory that have a base price of zero. Most of these fall in the category of Clutter. If you try to "sell" any of these items to a merchant, you will be prompted to "give away item". You do not gain any Mercantile points for giving items away. Zero value items are not listed in a merchant's inventory, making it impossible to retrieve any items given away.
 Quest Items
Many Quest Items have zero value as well as zero weight. You cannot even try to sell these items as they do not appear in your inventory when you are negotiating with a merchant, nor can you drop them. They must remain in your inventory until you have completed the related quest. The item may obtain a value after it is no longer tagged as a quest item.
The Mercantile skill determines your ability to negotiate for better prices when buying and selling items from merchants. The Base Price of each item is shown in your inventory. In the merchant's inventory window, however, the value of each item shown is your current offer. Clicking the Haggle button displays a simple sliding bar, which determines what price you are currently offering. The farther right, the better deals, and vice versa. "Deals" are presented as percentages, and unless the player has Master Mercantile, the buying price of items will always be higher than 100% of the Base Price, and the selling price always less than 100%.
The numerical range of this bar is determined by the merchant's Mercantile skill, while how high you can manage to sway them in your favor is determined by:
- your Mercantile skill
- the merchant's Disposition towards you.
All merchants, except when buying spells, will remember the last position in which you left the slider; and while mostly all merchants start at the lowest position, the game will usually set similar slider positions for everyone in the same faction. (E.g. If you buy something at 120% from someone in the mages guild, everyone else in the mages guild will automatically adjust to sell at that price.)
When you hit "Cancel", the changes will still take effect the next time you speak to that merchant.
 Non-negotiable Prices
There are a limited number of instances where you can not negotiate the price, typically involving services rather than items:
- prices of Houses (although all house upgrades are normal sales, subject to haggling)
- purchasing Horses
- armor and weapon repair services
- magical item recharging services
- beds (i.e., a room for the night)
- skill training prices are fixed at 10 times your current skill level
- item enchanting and spell making at the Arcane University
- buying lockpicks from Armand Christophe during the quest May the Best Thief Win.
 Merchants' Gold
When you are interacting with any merchant, their available gold will be shown in the bottom right corner of the screen (these values are also listed on the Merchants page and on the individual merchants' pages). This is not the total gold that the merchant has available, but rather the amount the merchant is willing to pay on a single transaction.
For example, say you are selling five expert retorts (base price 500 gold) to a merchant for 375 gold each. If the merchant has only 800 available gold, you will not be able to sell all five at once: a warning message pops up that the merchant does not have enough gold. All you need to do is just sell them two at a time, and you'll end up 1875 gold richer.
As the game progresses, you will start to collect valuable loot that exceeds any merchant's available gold. 1200 gold is the maximum gold available from any merchant and 1500 gold is the maximum from the highest level fence Fathis Ules, and those merchants typically have the highest Mercantile skills, with the exception of Varel Morvayn in Anvil.
Reaching Expert level Mercantile skill allows you to invest in a shop to increase the available gold by 500 and reaching Master in mercantile adds 500 gold to every shop (you may still invest after reaching Master thereby increasing available gold by 1000). However, ultimately many of the expensive items that you find can never be sold for anything close to their full value.