There is no great hurry to push out the Pro version as far as I can see, there are issue's that need to be resolved with the Sport version to make a Pro version viable, there are things that need to be changed.
As for pricing, take a look at the pricing structure for the Touring car STR4 Pro and Pro Sport, that may give an indication of the cost, but that is ONLY an indication.
Come on guys, do you want a pro which you would need to buy things for, except personal preferences like shocks maybe, or would you rather it be on the ball in kit form, I know which one I want.