One of the thinnest walled pipes I own came in a 'lot' I won on ebay back very early on in my then new exploration of pipes and tobaccos.
It's surprising that it's thin because, not only is it briar, it has a meerschaum liner.
It had been someone's very special pipe, as it had been repaired with a plug at the bottom, or maybe it was made that way?
It's become a very special pipe to me, anyway, because it smokes cool, is lightweight, and is a finely finished smooth Canadian shape. It seems to be perfect for staved (lightly rubbed and mostly intact) flakes.
Who ever burns out a bowl on the bottom?
On ebay, I like to see at least 1/4" of rim before I'll bid.
The Dunhill Shellbriar I won is closer to 3/16" but it wasn't high dollar, and is from 1954. I got it for $67.00.
Back then, I was 'speculating' on reselling my hard won acquisitions for profit. I was really kidding myself.
I did have a blast searching out inexpensive but reputable old pipes, and still do, but, I no longer think in terms of profit. My pace of acquisition has slowed way down. I have way more pipes than I really need, and they're cool to see there on their racks, waiting to be selected or remembered once again. (I've even got several unsmoked that I don't even look at, and mostly only because they're unsmoked.)