Currently, tickets purchased now will be valid until the end of 2019, though after the first day of use any additional days would need to be used within two weeks.
An equivalent ticket purchased on the current system would cost $95 per day.
A video accompanying the announcement shows an example of a 4-day ticket being purchased in mid-November 2018 for a price of $85 per day.
However, Disney has clarified that the video does not represent actual prices, so it’s unclear for now exactly how much the new pricing structure will cost.