Charles Martin, writing for Apple Insider;

Apple is significantly increasing prices for out-of-warranty battery replacements, this time for the iPhone 16 Pro models.
The new cost of an out-of-warranty battery replacement for the two larger models of the latest iPhone is $119, up from the $99 cost for the iPhone 15 Pro and Pro Max. The cost remains $99 for the regular iPhone 16 and iPhone 16 Plus.

Apple last increased the cost of out-of-warranty battery replacement with the iPhone 14 models in 2022. Prices went up from $69 to $99.

Iphone 15 and 16 owners will more or less just shrug this aside, since they have at least have 1 years of limited warranty and 2 years of technical support and hardware coverage if purchase AppleCare+ with their purchase. By the time the batteries of the iPhone 15 and 16 need to be replaced, Apple may have already increased the prices.