He is saying that if you intend to race an RC390 in the KTM cup it has to have been an original cup bike to start with. If you don't intend to enter into the cup series you can buy race parts for the street version. I would suggest going the street route if you aren't interested in the cup series as then you won't be limited to cup specs which has lower HP and mediocre performance accessories. My 2 cents.
I was offered $ 8,500 out of the door 2015 CUP version. Do I take it or wait for the 2017 street version and invest money on the racing parts ? what do you think guys.