DestinationCoupons offers a Grey Line Miami City Tour and Everglades Airboat Tour Adult Ticket in Miami, FL, for $45 via coupon code "CEDEST". (Click on "Buy Now Online" to book your tour.) That's $34 under booking directly. This 8-hour tour includes a city tour, airboat ride, and alligator show. Book this travel deal by December 31 for tours through the same date.
Of note: The coupon above also bags a child's ticket for $39.30. That's a savings of $30.