Skyrim Bartering/Trading Rates Guide
An interactive spreadsheet that calculates buying and selling prices based on various types of modifiers such as GMSTs, Speech, Enchating & Blessing Buffs, etc...
Download:
Skyrim Nexus: http://skyrim.nexusmods.com/mods/38116
Images:
Spreadsheet for use with vanilla base values: http://static.skyrim.nexusmods.com/mods/images/38116-1-1373354257.png
Spreadsheet with various supported mod preset values: http://static.skyrim.nexusmods.com/mods/images/38116-2-1373354259.png
Notes:
Some things I have discovered whilst making the spreadsheet utility:
The GMSTs "fBarterBuyMin", and "fBarterSellMax" do not function and modify values they were http://www.creationkit.com/Category:Settings.
It seems the defaults for these two which are "fBarterBuyMin=1.050000" and "fBarterSellMax=0.950000"
equates to 95 % for the maximum efficiency the player can sell an item for and 105% for the maximum efficiency a player can buy an item for, the game seems to always default to reading these values.
Ie. I would've had made good use of those two modifiers as I could've nutshelled an economy overhaul that's in one of my project plans that cuts down buying/selling prices of items to the barest essentials of gold.