Description: After selling to a merchant and reloading a saved game, the merchant money is not reset to the amount it is supposed to have in that saved game and is equal to the amount the merchant had before reloading.
How to reproduce: The order of the following steps is important. Do them in the order written. Save the game and check the merchant's money before selling goods. Sell goods to that merchant. Reload that last saved game. Check the merchant's money. Compare the two amounts.
Platform/Version: PC version 1.1.21.0.
Example: Save the game before selling goods. If the merchant has 750 gold and you sell goods worth 250 gold and reload that last saved game then the merchant's money will still be 500.
Workaround: Quit the game and exit to Windows. Restart Skyrim and reload the game.
Notes: Oddly enough, buying goods does not have the opposite problem.