The price is too hight i think also

And a good engine is an engine where you can find games made and selled commercialy with it !
if you don't find any, there is some problem with the engine.

For example : the old Blitz3D even have games made and selled with it today, Unity have a good amount of them (just go to it's showcase ), Even Ogre3D that is free you can find successfull great selled games, Torque 3D etc ...

With Gamecore, there's nothing, or give us the link to buy the game (or it's demo) ????