Interesting discussion....
As having to take IIT was part of the NAUI Technical Diving certification path, it took out all potential missed expectations between student and instructor. In my case, it also weeded out a group of 10 people, resulting in only 2 of us continuing on. When we got to the actual classes, equipment (own/borrow) was necessary (instructor did not furnish).
For me it was beneficial to do ITT as I was unsure if, due to my shoulder issues, I could actually reach valves for shut-down drills and procedures. Just tweaking the placement of equipment was time consuming, and would have not allowed a AN/DP class to proceed smoothly.
As said above, if the cost on an ITT class is troubling, then I'd think that Technical Diving is probably not going to be a pleasant experience to you (financially).
YMMV