The tools ended up being $45 for what are essentially two sockets. The price I found in my earlier searches was $60 to $90 (depending on foreign exchange rates.)
Prior experience says that when a special "tool" is not readily available, often that's because there's an alternate way of doing the task with generic tools. So - I was hoping someone had a trick to hold the "cone" steady while I tighten the locknut with a standard socket. I was also posting as a form of product review.
There's ten or so LBS's that I'd consider local enough to bike to, but I've not found any of them to be the perfect LBS for me. Perhaps they've fragmented the local market too much...