This is probably a targeted offer. I checked it using my HOYTS rewards account and it showed $1 for a standard ticket and $5 for an Xtremescreen one.
*$1 ticket is valid for standard sessions only. $1 ticket is valid for 30 days after offer is received. Online booking fees and Xtremescreen and D-BOX surcharges apply. Not available in HOYTS LUX, or for special screenings. Limit of (1) one ticket at $1. Offer may take up to 2 hours to appear on your account. Available online and in-cinema. Members must include their Rewards member number as part of the ticket purchase to be eligible for the offer. HOYTS Rewards benefits are for personal use only and are not transferable, not redeemable for cash and are non-refundable.
I'm pretty sure that's because you have 6000 points to spend?