I just called and spoke to an extremely helpful CM about this event! (I only called b/c one of the links you posted says booking was now available. It's not

) BUT I did get some good info...
It will be offered twice nightly (8 pm and 10 pm) in October, Thursday
through Sunday, plus the 30th and 31st.
No discounts available. Confirmed the $38/$22 pricing (+ tax). Prepay at time of booking.
2 day cancellation policy.
Can be booked 180 days in advance of the date you are booking.
Is booked through 407-WDW-PLAY, Tours option.