Why two diff values for identical items?

Hi,
Could someone tell me why two identical items in every way have two different values to the merchant? The last line for an item is the Value in gold if you were to sell to merchant.

I know it doesn't mean anything when trading with other people, but why two different values if they are identical?

There must be a reason for this.

Thanks!

Cause they are all randomly generated, when they drop, from a list of possible values. The randomness is not just limited to damage/req/skin/mods.

I believe the merchant value for identified items has to do with the attribute requirement, and the level of the monster who dropped it. I remember two white tall shields armor 16 req 9 tactics had different values because one dropped from a lvl 20 monster and another from a lvl 24.

This is incorrect. The merchant value V of an item is determined through the equation V = C * (V_base + P * V_range) where

C is between 0 and 1 depending on how close to max the stats (not requirement!) of the item are
V_base is the minimal value which depends on rarity (50 for white and blue, 100 for purple and 200 for gold)
V_range gives the range of variation and depends on rarity as well (much harder to give exact values, probably 100 for white and blue, 200 for purple and 400 for gold)
P is a random number between 0 and 1 drawn from a distribution which heavily favors the low end (most likely P_uni^N where P_uni is the uniform [ 0, 1 ] distribution and N some reasonably large integer)

Or, to sum up the above - it's random like everything else (in a pseudo-random way.)

if you like confusing equations, then its not random refer to tmakinen's post but if you don't like big confusing equations then its random.

Damn - I was so just going to say that and you beat me to it!!!!! :-)

I think the question has been well and truly answered.