Tri-X 400 (as it has evolved over the years) has had more shots taken on it by professional photographers for professional uses than any other film you could possibly buy new today.

It may not be the most popular film now for professional use (although I wouldn't be surprised if its numbers are still very high) but it is certainly of professional calibre, marketed to professionals and used by professionals.

And with respect to the rest of this thread, and the discussions about price, everyone here seems to be ignoring one important fact.

There is no longer anything resembling a rational distribution system for Kodak materials and, to a great extent, it is the distribution system that determines the price that consumers pay.