last year they had this buy 1 get 1 50% off deal on call of duty modern warfare 3, assassins creed revelations, rayman origins and another game i can't remember

i got call of duty and rayman and was expecting it to be $90, it was $60 total

was it a glitch in the system or am i not reading this right? i hope to get black ops 2 and halo 4 for $60 total