We can add price range in product schema. low and high price

gistfile1.txt

add_action( 'after_setup_theme', 'add_my_custom_meta_field' );
function add_my_custom_meta_field() {
	add_filter( 'wp_schema_pro_schema_meta_fields', 'my_extra_schema_field' );
	add_filter( 'wp_schema_pro_schema_product', 'my_extra_schema_field_mapping', 10, 3 );
}

/**
 * Add fields for mapping.
 *
 * @param  array $fields Mapping fields array.
 * @return array
 */
function my_extra_schema_field( $fields ) {
    $fields['bsf-aiosrs-product']['subkeys']['highPrice'] = array( // `bsf-aiosrs-book` used for Book, `bsf-aiosrs-event` will for Event like that.
		'label'    => esc_html__( 'High Price', 'aiosrs-pro' ), // Label to display in Mapping fields
		'type'     => 'number', // text/date/image
		'default'  => 'none',
		'required' => true, // true/false.
	);

	$fields['bsf-aiosrs-product']['subkeys']['lowPrice'] = array( // `bsf-aiosrs-book` used for Book, `bsf-aiosrs-event` will for Event like that.
		'label'    => esc_html__( 'Low Price', 'aiosrs-pro' ), // Label to display in Mapping fields
		'type'     => 'number', // text/date/image
		'default'  => 'none',
		'required' => true, // true/false.
	);
	 $fields['bsf-aiosrs-product']['subkeys']['offerCount'] = array( // `bsf-aiosrs-book` used for Book, `bsf-aiosrs-event` will for Event like that.
		'label'    => esc_html__( 'Offer count', 'aiosrs-pro' ), // Label to display in Mapping fields
		'type'     => 'number', // text/date/image
		'default'  => 'none',
		'required' => true, // true/false.
	);

	return $fields;
}

/**
 * Mapping extra field for schema markup.
 *
 * @param  array $schema Schema array.
 * @param  array $data   Mapping fields array.
 * @return array
 */
function my_extra_schema_field_mapping( $schema, $data, $post ) {
         $schema['offers']['@type'] = 'AggregateOffer';
         $schema['offers']['price'] = '';
    if ( isset( $data['highPrice'] ) && ! empty( $data['highPrice'] ) ) {
		// For date/text type field
		$schema['offers']['highPrice'] = esc_html( $data['highPrice'] );

		// For image type field
		// $schema['workExample'] = BSF_AIOSRS_Pro_Schema_Template::get_image_schema( $data['work-example'] );
	}     
	if ( isset( $data['lowPrice'] ) && ! empty( $data['lowPrice'] ) ) {
		// For date/text type field
		$schema['offers']['lowPrice'] = esc_html( $data['lowPrice'] );

		// For image type field
		// $schema['workExample'] = BSF_AIOSRS_Pro_Schema_Template::get_image_schema( $data['work-example'] );
	}
	if ( isset( $data['offerCount'] ) && ! empty( $data['offerCount'] ) ) {
		// For date/text type field
		$schema['offers']['offerCount'] = esc_html( $data['offerCount'] );

		// For image type field
		// $schema['workExample'] = BSF_AIOSRS_Pro_Schema_Template::get_image_schema( $data['work-example'] );
	}
	return $schema;
}