The following tables list what prices a merchant of a given skill was willing to offer for both the sale and purchase of a 100 septim pearl. Measurements were taken with a character with a Personality and Luck of 40.  Disposition was 45 in all cases.  The player's mercantile score was varied, as shown on the tables.




Merchant Mercantile 5
                           Buy Offer                 Sell Offer
PC Merc.
20                            95                            54
40                            81                            67
60                            70                            70
80                            57                            57
100                           45                            45

Merchant Mercantile 20
                              Buy Offer             Sell Offer
PC Merc.
20                           104                            45
40                            91                            58
60                            79                            70
80                            66                            66
100                           54                            54

Believe it or not, most merchants' Mercantile score range from between 5 and 20, so this data is representative of how commerce works for the majority of the game.  Notice how player mercantile scores of greater than 60 actually lead to a decrease in purchase offers.  This is the infamous "mercantile bug" (although we'll see in a moment that it's not really a bug with the mercantile skill itself).  Since the player spends a lot more time selling than buying, this means that a high mercantile score actually puts the player at a disadvantage, an annoying outcome.

Also, be aware that through haggling, you can easily alter the prices given above by about 10% in your favor.  This means that when the buy and sell prices are close together, the player can actually make money by simply trading the same item back and forth with the merchant, whom stupidly keeps buying the item at a higher price than he sells it.

Something interesting happens somewhere around a skill of 40.  The "mercantile bug" dissappears!  A higher merc score for the player always results in better prices when dealing with a reasonably skilled merchant. Check out these data:


Merchant Mercantile 40
                           Buy Offer                 Sell Offer
PC Merc.
20                             123                          26
40                             110                          39
60                              98                          51
80                              85                          64
100                             73                          73



Conclusion:  To make mercantile a viable player skill, most merchants must have a minimum mercantile score of about 30-40.  Even this is probablt stilltoo low, however.  Notice that a player witha Mercantile of 100 can make a profit by buying and selling the same object to the merchant over and over, collecting the haggling difference each time.  No-one should be able to convince a merchant to do something that stupid, no matter how good his trading skills are.



Merchant Mercantile 60
                              Buy Offer             Sell Offer
PC Merc.
20                             129                           20
40                             116                           33
60                             104                           45
80                              91                           58
100                             79                           70

At a skill 60, the merchant is starting to hold his own, although a PC with a skill of around 100 can still extort infinite money out of him by exploiting the back-and-forth bug, although it's certainly harder now.  Look waht happens at really high scores:

Merchant Mercantile 80
                            Buy Offer                Sell Offer
PC Merc.
20                             141                            8
40                             129                           20
60                             116                           33
80                             104                           45
100                             91                           58

Merchant Mercantile 100
                              Buy Offer            Sell Offer
PC Merc.
20                             154                          1
40                             141                          8
60                             129                          20
80                             116                          33
100                            104                          45


At the higher end of the skill scale, the merchant becomes a brutal businessman.  No amount of haggling can force the merchant to buy and sell at a loss.  A truly skilled PC can force the merchant to meet him midway in the price range, but beginning PCs will be blown out of the water.

Conclusions:   The so-called "mercantile bug" was really just a result of the NPCs mercantile scores being entirely too low.  A minimum score of about 30 is neccessary to avoid the mercantile bug, but higher values are desirable, becasue they eliminate the back-and-forth bug, and generally make the merchants sharper businessmen.  However, it is also desirable to still have a substantial number of weaker merchants, or beginning PCs will never be able to get up off the ground.


The effects of Disposition were also measured.  The same skill 100 merchant was tested again, this time after having had his diposition raised to 100:


Merchant Mercantile 100   Disposition 100

                             Buy Offer                Sell Offer
PC Merc.
20                            120                           30
40                            107                           42
60                             95                           67  
100                            70                           70

The effects are similar to what would have happend if the merchant had lost about 60 points off of his skill.  Notice that it is now possible for the player to extort an infinite amount of money out of the merchant by trading a single item backa and forth.

Merchants can be protected from persuasion and bribery by raising their Speechcraft scores.  Currently, their Speechcraft scores are entirely too low, and even a begginning character can generally admire most merchants in abject helplessless.  This is bad for both the economy, and for the Speechcraft skill itself (if you can accomplish just about anything with a Speechcraft skill of 40, why would anyone ever take it as a primary skill?).

When the player's Speechcraft skill is equal to the merchant's, the PC can generally push the Disposition up to about 60, which isn't so bad.  

The effects of bribery were investigated.  The merchant was granted a mercantile and speechcraft skill of 100.  The PC, with a meager speechcraft skill of 20, was able to consistantyl bribe the merchant to 100, oftentimes using only 10 septim bribes.  The merchant never declined a 1000 spetim bribe.

It is a bit strange that a merchant would accept a one-time bribe to permanently lower his prices by about 33%.  Bribery is simply too powerful as written.

The effectiveness of bribery can be altered in the Game settings menu. The gamesettings fBribe10Mod, fBribe100Mod, and fBribe1000Mod were lowered from 35, 75 and 150 to 20, 40, and 60.  Bribery is still an effective and valuable tool, but it is no longer a magic carpet.  It can be used to modestly improve disposition with someone who has a similar Speechcraft skill as the player, but it cannot be used to lull an equally skilled merchant into abject submission.