Pathology maybe usually $100 for a tissue exam, but I've seen a routine mole biopsy need $1,500+ (wholesale) exams after referral to an academic center because there was something off that required further workup. This happened 1 time in 10 years.
Anesthesia knows that a breast augmentation will usually be no less than $X, but if the patient has an anesthesia reaction and decompensates and needs 4 hours of one on one time with an MD its going to be a lot more. Very, very rare.
You get the idea, its often not possible to know until you do the procedure. Even more when surgery is involved because imaging is not 100% and you may wind up with a much more complex procedure than you bargained for once you cut someone open, or a complication like a perforated bowel during colonoscopy, etc.
Finally, most of these people don't talk to each other -- so the pathologist has no idea what the surgeon is charging and neither of them the hospital nor radiologist.