Filter revisioned meta fields to include the `product_price` field

enable_revisions_for_product_price.php

<?php
/**
 * Enable revisions for product_price
 */
function enable_revisions_for_product_price_field( $revisioned_keys ) {
	if ( ! in_array( 'product_price', $revisioned_keys ) ) {
		$revisioned_keys[] = 'product_price';
	}
	return $revisioned_keys;
}
add_filter( `wp_post_revision_meta_keys`, `enable_revisions_for_product_price_field` );