In non-tech cases, my impression is that upstream billing isn't taken as solid proof of the amount of damage incurred. For example you might have a very expensive contract with a visits-your-house personal mechanic who you've agreed will be your exclusive car-repairer. Thus when you're hit in an accident, you automatically incur a large bill of $X, due to your pre-agreed subscription with the mechanic. But for either civil or criminal damage computation, a court would normally determine how much damage was caused by looking at what the repair cost would've been with a "normal" mechanic at prevailing rates instead.