When it comes to factoring the cost of making a pipe there are so many variables that there is no one objective answer. Weber was giving a price for a basic machine made factory pipe, turned out in multiples, with a molded stem.
It was capable of carrying out its basic function, allowing the smoker to smoke tobacco. At that level, $120 for a briar pipe isn't out of line. There's the manufacturers' cost, the distributors' mark ups, and the retailers' mark ups. There's little hand work, little concern for quality control, etc, because there isn't the margin at that price point for much more. Cobs can do the same thing, for a lot less money because the materials are cheaper, and the construction is more rudimentary. And cobs also do a good job of providing the smoker with a good smoke.
But buying a pipe isn't solely an objective choice. Read the posts here and on other enthusiast's forums and you encounter a wider range of subjectivity. With one-of-a-kind artisan pipes, the price range is all over the place. At the high end, where prices can soar into 5 figures, people are buying a lot more than function. They're buying art, design, esthetics, history, perceived quality of execution, bragging rights, exclusivity, brand, and/or a lot more subjective considerations.
Also at the high end, a carver may have a lot more wastage, briar that doesn't meet that carver's metric for quality. So there's a much higher cost for materials, as well as time and labor lost to the vagaries of the wood. You're not just paying for the pipe, but for all of the costs involved with the duds.
Asking what a pipe should cost is like asking what a car should cost. It all depends on what you're looking for. If all you need is a device for delivering nicotine, you can find that at a modest price point. If you're looking for more, the price starts to climb.