I have seen where some guys have purchased the tab pro for $20 lifetime. Do you need a coupon or just wait for a special?  I have seen to many pros and cons on it to pay the going price of right at $40.  
Not sure 'bout that, but I got lifetime access to TabPro by just submitting and getting my first tab approved, TabPro is just a online Guitar Pro with custom soundbanks, you don't need to download GP tabs with TP.
How does this thing Works ??!?!