class WC_Settings_Tab_Demo {
    /**
     * Bootstraps the class and hooks required actions & filters.
     *
     */
    public static function init() {
        add_filter( 'woocommerce_settings_tabs_array', __CLASS__ . '::add_settings_tab', 50 );
        add_action( 'woocommerce_settings_tabs_settings_tab_demo', __CLASS__ . '::settings_tab' );
        add_action( 'woocommerce_update_options_settings_tab_demo', __CLASS__ . '::update_settings' );
        add_action('woocommerce_process_product_meta', __CLASS__ . '::process_meta');
    }


    /**
     * Add a new settings tab to the WooCommerce settings tabs array.
     *
     * @param array $settings_tabs Array of WooCommerce setting tabs & their labels, excluding the Subscription tab.
     * @return array $settings_tabs Array of WooCommerce setting tabs & their labels, including the Subscription tab.
     */
    public static function add_settings_tab( $settings_tabs ) {
        $settings_tabs['settings_tab_demo'] = __( 'Pricing', 'woocommerce-settings-tab-demo' );
        return $settings_tabs;
    }
    /**
     * Uses the WooCommerce admin fields API to output settings via the @see woocommerce_admin_fields() function.
     *
     * @uses woocommerce_admin_fields()
     * @uses self::get_settings()
     */
    public static function settings_tab() {
        woocommerce_admin_fields( self::get_settings() );
    }
    /**
     * Uses the WooCommerce options API to save settings via the @see woocommerce_update_options() function.
     *
     * @uses woocommerce_update_options()
     * @uses self::get_settings()
     */
    public static function update_settings() {
        woocommerce_update_options( self::get_settings() );
    }


        /**
     * Uses the WooCommerce options API to save settings via the @see woocommerce_update_options() function.
     *
     * @uses woocommerce_update_options()
     * @uses self::get_settings()
     */
    public static function process_meta() {

    }


    /**
     * Get all the settings for this plugin for @see woocommerce_admin_fields() function.
     *
     * @return array Array of settings for @see woocommerce_admin_fields() function.
     */
    public static function get_settings() {

    $settings[] = array( 'name' => __( 'Margin settings', 'text-domain' ), 'type' => 'title', 'desc' => __( 'The following options are to configure our margin on top of prices', 'text-domain' ), 'id' => 'wcslider' );

                $settings[] = array(
            'name'     => __( 'Canvas', 'text-domain' ),
            'desc_tip' => __( 'Margin profit in percents added on top of Canvases!', 'text-domain' ),
            'id'       => 'canvas',
            'type'     => 'text',
        );
        // Add second text field option
        $settings[] = array(
            'name'     => __( 'Framed Posters', 'text-domain' ),
            'desc_tip' => __( 'Margin profit in percents added on top of Framed Posters!', 'text-domain' ),
            'id'       => 'framed',
            'type'     => 'text',
        );

                    // Add second text field option
        $settings[] = array(
            'name'     => __( 'Posters', 'text-domain' ),
            'desc_tip' => __( 'Margin profit in percents added on top of Posters!', 'text-domain' ),
            'id'       => 'posters',
            'type'     => 'text',
        );

        $settings[] = array( 'type' => 'sectionend', 'id' => 'posters' );


        return apply_filters( 'wc_settings_tab_demo_settings', $settings );
    }
}
WC_Settings_Tab_Demo::init();

<?php print get_option( 'canvas', true );?> //23
<?php print get_option( 'posters', true );?> //233
<?php print get_option( 'framed', true );?> //21