Just saw that Intrepid offers 50% off Antarctica trips, which is an awesome deal on an amazing experience if you can afford it; however it's still a bit over my budget. Will drop a link in a comment for those who are interested. :)
Another promotion they're running at the moment and is more affordable is 20% off Dragoman trips, including the "Gorillas & Chimps In Depth" with $400+ savings, which has got very good reviews.
"For a limited time, we’re offering up to 20% OFF* Dragoman operated trips in South America & East Africa. All you have to do is book by 10 October 2016, travel before 01 July 2017 and leave the rest to us. The open road is ready for you. Buckle up, adventurers."
The East Africa tour is a 3 week trip departing from Nairobi, Kenya and visits the savannah and rainforests of Rwanda and Uganda as well, during which you will search for gorillas, see rhinos up close, taste traditional African cuisine, trek through amazing wildlife and visit museums. Most of the trip you'll spend sleeping at campsites (17 nights).
The promotion is available on trips departing 28th November & 18th of December 2016, and next year from 7th of May and 2nd of July for a total of $4,105 per person (twin share, excluding flights) if you book by the 10th of October.