25% of what, and where are you getting that number? JAMA studied this on an encounter-by-encounter basis and found BIR costs were in the tens of dollars for normal visits to low (100-300) for inpatient surgery.
Price transparency is a real problem. Overbilling is a real problem, so is overprescription. Important to keep in mind that those are on the provider side, not the payer.
25% is perhaps on the high side of estimates, but perfectly plausible. If you prefer citations from JAMA: https://jamanetwork.com/journals/jama/fullarticle/2785479