Why are vendors offering (much) less gold for items than expected? [duplicate]
Solution 1:
The value in your inventory is the worth of the item. Vendors will give you a percentage of that value based on your speechcraft skill and other factors. Likewise they will sell it for a multiple of that value.
Specifically the price is:
Sell price = [ value of item ] / [ 3.3 - (1.3 * [speech skill]/100) ] * [(1 + Haggling %) * (1 + Allure %) * (1 + Fortify Barter from potion) * (1 + the sum of Fortify Barter from equipment + Fortify Barter from Blessing of Zenithar)
From the UESP Wiki.