In January 2012, IBM acquired the Green Hat tool set, including GH Tester. Now, GH Tester is called IBM Rational Test Workbench. The product is available only for a single user and its price vary from 4275.50 to 16343.50 Euros. These prices are without taxes and the license is available for 12 months. You can check all the features and the prices on IBM web page.