Mystere by Cirque Du Soleil at TI (Tresure Island Las vegas) is having a 2 for $100 fall special.
There seems to be limited seats at this rate, but try different rates and times.
The promo code is SUMMER
2 strange things that I noticed. It is says summer $50 promo but ticket prices are $55, and on the main TI Mystere site it says Fall special, but promo code and information while booking says Summer.
Anyways it is a good price for a good show. Enjoy!