To celebrate Tropico's 20th anniversary, Humble Bundle are offering a special bundle including complete editions of past editions of Tropico as well as the current Tropico 6 and most of its DLCs.
1 Item Bundle: $1.36 (at time of posting)
6 Item Bundle: At least $16.41 (at time of posting) - Tropico 3: Gold Edition and
Full 8 Item Bundle: At least $16.42 (at time of posting) - Everything in the above 2 bundles and
Considering Tropico 6: El Prez Edition is currently A $67.95 on its own, this is one of the more outrageously bargain HB bundles I've seen in a long time. If you've been waiting for a time to purchase/start playing Tropico, this is the perfect opportunity to do so.