Update: This event is now finished.
Hey! Right now there is an event running from . It's called Summer Rallye II.
It pretty much works like Ladders & Snakes. Just login at the page and every day you can dice once and move to the correspondending number. There are places, where you go further or go back. At the end of the event, you get the prices when you crossed over these specific price spots 
So pretty much, good luck.