As others have said, the most expensive pipes will be from the Danish masters, Bo Nordh, Sixten Ivarrson, Lars Ivarrson, Jess Chonowitch, Teddy Knudsen, Anne Julie etc.. Some of the most collectible pipes will come from two companies though, Dunhill and Castello, both of these companies produce top shelf pipes and have a range of prices, from only expensive to truly ludicrous. As far as the best smoking pipes, I wouldn't touch that with a ten foot pole, too many personal opinions.