08 Jun 2011 at 22:57 - 7
Value is determined by "How much would he need to pay in order for me to be happy" and "How much am I willing to pay". Such things are for many items impossible to determine, say the plagueborn staff is very nice indeed and it's an incredibly rare drop. But there may only be 10 players in the entire game that are interested in a Q9 20\19 or 20\20 Plagueborn Fire Staff.
Now, some of those players don't really care if the staff is 20\19 or 20\20 they're happy regardless. After all it's a nice staff and 1 off isn't ever going to determine whether you win or loose. Say 2 of them don't care, 2 are happy to pay less then they'd have to for a 20\20 and the other 6 are only into 20\20 ones and able and willing to pay.
Now these numbers may be pulled out of my arse, but theyre probably not all that far from the truth.
In other words, doesn't really matter how much you ask cause nobody actually has a good answer for you.