What Roth said.
Either of these fellows will be square with you and, if you are looking to maximize value, you will find that selling through a reputable dealer like these guys will enable you to command higher prices that more than account for their commissions/purchase (depending on their approach).
I would pay considerably more for a pipe form one of these fellows than form an unknown EBay seller, because I know their representation of a pipes provenance and condition will be spot on.