Regardless of what any guide tells you, the value of a chip is determined by what you are willing to pay.
By you having a current value guide you know not to bid on a particular auction.
One could possibly say that the seller might not have a current price guide but I am not making that excuse for the seller.
The seller however is a club member and bound by the club code of ethics.
Have you tried to e-mail him?
If he is upstanding, he will amend his auction to reflect the current value