It wouldnt be worth it at the moment. Having professionly evalutated engines, I can tell you that there are simply none, with a real license, in that price range.
You'd be better off using an open source alternative, but if you insist on paying Torque is ok.
Edit: And before people have a rant about GPL code there are ways around it. I know, I've worked on several projects based around the Linux Kernel.