If your shifter is like new, it won't make a huge difference no, but my bet it's that it's not... I've never seen one (and I'm a Porsche Tech so I get to see a LOT !) in good condition.
So it will make a huge difference !
The price is "high" because it's a fairly small production, I can't afford to make 5000 of them to get a real low price !
The complete kit shifter + lever is still cheaper than many aftermarket short shifter
Ben