I think (hope) increased transparency will be the expectation and practice as time progresses, in light of how consumerism has evolved in this nation (U.S.), and the fact that ballroom dancers are increasingly cost-conscious and it is becoming less common for them to just wave the magic wand and say, "sure, just tell me how much to write the check for."
My experience has been on the lower end of the transparency curve. I have always been given a base price ($y,000), which may or may not include a specified number of heats (10 or so), and then $x per heat. There was no breakdown of $x between what the comp actually charges and the studio cut, and no breakdown of the base cost into hotel/transportation/meals, etc. I did have one comp where the studio offered a non-VIP (tee hee) option where you did not stay at the hotel and certain meals were not included, but otherwise those components have not been removable (for me). Of course, I've never bothered to ask to remove those, but I feel certain the answer would be "no".
Having said that, my studio is always upfront with pricing information because they know I'm going to ask, and that it's going to be a much more painful conversation for them if I have to pry it out of them. (A former instructor once told me he quickly figured out that the best approach with me was to say, "Hey, here's this event I would like you to consider, and here's how much it is." i.e. just get it out of the way upfront).