Paul,
Yesterday I was at Castello in Cantu. I was able to watch many of the 120 steps taken to create a Castello Pipe. From sheet, then cut into rod ( various sizes ), drilling, to turning the tenon, to shaping the basic stem shape, to rough finishing the stem shape, to shaping the button, to inserting the logo, and final polishing take way more time than you think. That is stem for a new pipe, NOT starting with a bowl and now having to take into account the exact mortise length, tenon diameter, shape the stem so the shank and stem junction match ( without re shaping the shank ) and finishing etc. You are now speaking of a full days labour for the stem you require. !00 Euro is not out of line. I wouldn't do it for 100 Eur0
Regards
Michael J. Glukler