It's hard to say, if you list something for $10 and it sells for $90, it's worth $90. It all depends on who's looking for the item in that 7 day auction window.
I listed auctions for shoes at $79.99, didn't sell, 7 days expired, re-listed them at $99 buy it now for 30 days and the next day it sells at $99, 20% more. That's not to say, I could of listed it at $129.99 and it might of sold at that price too. It's all about the right buyer seeing the item for sale at the right time. In the case of auctions, you need 2 of the right buyers seeing the item, in that 7 day time window. Obscure, Items it's tricky to get those 2 right buyers, so if you know the worth of an item approximately, you can start that auction off where it should start and hope for the best.
Now items, like iphones, silver bars, etc. You can put those on a 1 day auction and you'll get a decent price for them, just because a large number of people are looking for them.
But a Ming Dynasty pillow made during the eleventh emperor's rule in the 1500's, like this guy is selling for $130.
http://www.ebay.com/itm/321323369026?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AITNo one bought it? Now I'm assuming, the guy doesn't know Chinese, because if he knew how to read, he would of wrote a better description for it. And B, what type of value do you place on this item? I have no clue. The only reason I seen this is because I have the same item but made during the 5th emperor's rule, dated from 1425 to 1435.
Is his 500 year old Ming Pillow worthless because it didn't sell? I don't know and is the 600 year old one I have worthless too? I don't know, I would like to think it's worth a lot more then $130.
That's something that worth point might be able to tell you. But I have a feeling i'm going to need to seek out a person that specialize in the Ming Dynasty period to get a number from.