You know, that's a good question, I often run into the sellers that don't like to reveal their reserves (in my case it is usually 95% don't reveal - 5% do
)The reason they state is so that the auction is fair to all bidders.
I don't see what is unfair about stating your reserve.
Perhaps the seller is hoping that by not revealing the reserve, it will encourage "nibblers" to continue to bid in order to reach the reserve - perhaps they feel that if the nibbler knew what the reserve was up front, they might not bid at all (?)
These are just my off the cuff theories. I would be interested to hear from some other people on the forum about this.
-bjt