If something is magically $500 cheaper on a $2000 item, there is always a catch/hidden cost I've found.
GCG price from what i can see is: $2312, incl actuator...
Procharge price makes no mention of actuator/bracket etc, add another $150+... $2215+
Now here is the nice part... Join SAU NSW, you get a 10% discount (on GCG) & the price is $2152 if you really wanna save $60
(I'm assuming you are going internal gate, cbf pricing it up external)
As i said, for something to be over 20% cheaper on such low margin items like turbos - there often something missing.