Buying Traktor Scratch Pro Upgrade / then selling TP

Hey guys!
I own Traktor Pro (the 99 € updgrade from Traktor LE included with the VCI)
I would like to purchase the traktor sratch pro upgrade at 500 €.
Would I be able to sell my copy of traktor pro after?
WIll I still need my traktor pro serial or will I only need my new traktor scratch pro serial?
WIll th the guy buying my traktor pro will be able to use it without any problem?

Is there a difference inside the software and serial number between a regular and an upgrade version? are is it just a difference when you buy it?

Thnaks guys!

any traktor scratch owners??