They want to inspect the device and make sure the hardware and chassis of the phone is ok. If they find anything damaged or not working they will want you to fix themissues before they'll touch the battery. When I had Apple replace my iPhone X battery they had to replace the earpiece due to an issue during replacement and they didn't charge me for anything but the battery.Apple wants £85 but they saying is estimate, I’m sure the had a price list for repairs before on website which showed the price and now is estimate?