Whilst there is no official price stated anywhere on Apple’s site, you can bring your device into a nearby Apple Store or Apple Service Provider to evaluate a price for it. And of course, if the evaluated price is too much, you can refuse the repair from apple and try and find a specialised third-party repair store that can repair the glass at a cheap price. But please do this at your own risk! You don’t want dodgy looking third-party repair stores randomly opening the phone and start inspecting, removing and adding parts. This could damage the phone more if the parts turned out to be non Genuine Apple OEM parts. Having non Genuine Apple OEM parts inside the phone can make it unusable, and you will need to buy a new phone.
To reserve your appointment with an Apple Store or Apple Service Provider, click on the link below:
iPhone Repair and Service - Apple Official Support