On July 3, Valve released The International 2020 Collector’s Cache and a few days later, Redditor Kraizin calculated the probability of obtaining its rare sets.
According to his calculations, the chance of getting a set for Tiny on the first 13 treasures is more than 50%. With the same probability, the first 22 chests may potentially have a set for Mars to drop out. Upon opening at least 44 treasures, there is a 50% chance you can get a set for Mirana.
Chances to get one of the rare sets when buying 15 treasures:
The International 2020 Collector’s Cache is priced at RM11 ($2.49). The treasure will be available for sale within 30 days. For opening 15 chests, the user will automatically receive 36 levels of Battle Pass 2020.