I have seen the exact opposite. Kingsnake prices are generally higher than what the the show prices are.
I bought a female het g-stripe from ECRB at the Hamburgh show for much less than KS prices. I also picked up a male piebald at that show for much less than you could find on KS.
Seems to me it works both ways.
From what I have seen on KS it seems like over priced animals are the norm.