Based on a previous post, the COST IS KNOWN.
The original complaint was that the battery in the iPhone had been discharging excessively.
When that poster sent his iPhone in with what was stated to also be a mere "ding" in the back of the iPhone back panel Apple, and maybe rightfully so, determined that the Warranty had been voided and charged that iPhone owner $279.00 for a repair. Rationale being that the iPhone owner had tried to open the phone to either look at the battery or see if he/she could fix the battery problem unilaterally. The back panel was pressing against the battery when Apple received the unit.
Appears that Apple had been able to verify that the iPhone back panel was either removed or that someone had attempted to remove the back panel and that was also damaged in the process.
mikeab 🙂