The Kardashians Take a Ride on Dan Bilzerian's Dirty Bird

The Kardashians started off their Costa Rica trip in style ... hopping on Dan Bilzerian's infamous party plane for the ride there.

We're told the Kardashians rented out Dan's 16-seat Gulfstream G4SP to take them to the tropical country. The plane has certainly had its share of hot babes roaming the aisle.

The trip wasn't cheap -- $120,000 round trip.

Hangers-on not included.