How much to replace an iPad Pro screen?

For qualifying devices for which hardware support is available, you can establish the cost of an out-of-warranty repair for your country/region here:

iPad Repair & Service - Apple Support

Apple store locations DO NOT repair iPads. Only offer in/out of warranty device replacement.

If no paid AppleCare+ warranty, which would cover any user damages, very expensive to replace an entire iPad for user damage that is not covered under a paid AppleCare warranty plan.

Without a paid warranty, costing approx. 60% of that iPad Pro's original OEM price from Apple, for a replacement iPad, in lieu of an actual repair.

Start here.

iPad Repair & Service - Apple Support