How to display the calculated priced of commerce products?
When a price field is rendered using the "Formatted price" display formatter, it has a setting for you to choose between displaying the original price as loaded or the calculated sell price for the current user. That second one is the default, so as long as you are using product pricing rules properly (as indicated in the comments), this should just work for you.

If for some reason it isn't you'll need to find and review your display settings for the price field on your various product types. Because the price field that appears on a product display comes from the product entity directly, you have to adjust its field display settings there instead of on the relevant node type. You should find them under Administration > Store > Products > Product types. Click the manage display link beside your product type and see what it says.

If you get stuck, feel free to join us in the #commerce channel in the Drupal Slack!