Sounds like a good deal for the dealers. You buy at Costco, they get to deliver it at the dealer and collect the PDI fees. They have you for most of the after sales sales at 20% off list. Good deal for the dealers IMHO. MA and Pa should be pretty happy unless they sell Yamaha or Suzuki or Honda.
You dont buy the motorcycles at Costco they are only displaying, you have to go to the dealer to see the price.