The microdata I am seeing is being set by Yoast SEO. I see you may also be using the Facebook for WooCommerce plugin. That plugin doesn’t use the microdata to sync the products. It uses the settings in the plugin, pulls the data directly out of the database, and syncs with Facebook every 15 minutes using ActionScheduler with the wc_facebook_regenerate_feed hook. If you have the plugin configured correctly and connected to your catalog, it should create a CSV in wp-content/uploads/facebook_for_woocommerce every 15 minutes and automatically update on Facebook. That CSV should include the price.
If you want custom tags to show in what Yoast outputs, you need to add your own meta data presenter per this documentation as they removed the wpse_opengraph action with no replacement: https://developer.yoast.com/blog/yoast-seo-14-0-adding-metadata/