Busch Gardens and its sister park SeaWorld are having a flash sale this week that can save you more than $50 on admission tickets, but the offers expire Sunday. Calling it a BOGO Back to School sale, Busch Gardens announced Tuesday you can buy one single-day ticket at $89.99 and get a second one free. It must be used by Sept. 16, and the sale ends Sunday at buschgardens.com. Both SeaWorld and Busch Gardens are offering a two- and three-park ticket deal this week that also expires Sunday. Buy one ticket ($99) and get a second ticket for half price ($49) that can be used at SeaWorld, Aquatica water park, Busch Gardens or Adventure Island by Sept. 16. seaworldorlando.com. This week, SeaWorld is also hosting a Thrill Fest Ride Night on Friday, an extended night of riding its coasters Mako, Manta, Kraken Unleashed and Journey to Atlantis. The park will open until midnight with an extended happy hour. Click here for more details. Contact Sharon Kennedy Wynne at [email protected] Follow @SharonKWn."target="_blank">Contact Sharon Kennedy Wynne at [email protected] Follow @SharonKWn.