It is listed at $60 on Amazon, and that's not including the special USB dongle you need to plug your bass or guitar into your PC (if I searched correctly).
I would say that 20 bucks seems pretty fair to me, if the key is legit.
Maybe some other CAG can shed some more light into this but from my own view it seems like a very fair deal to me. I don't know if there may be a price drop in the near future, and I didn't check eBay either.
Good luck though with whatever you decide to do my man.