Just found this while going through Canberra Times. Dendy Cinemas are bringing the tickets down to $6.60 as they were in 1989. On Dendy's website it says:
Back to 1989 Prices. In honour of back to the future, we're taking prices back to what they were in 1989. You'll pay the retro ticket price of $6.60 for all Sundate sessions on October 25
Offer only available on Sunday October 25 after 5pm, excludes group bookings, special events, previews, premieres, 3D sessions, Dendy Lounge and Dendy Premium sessions and not to be used in conjunction with any other offer.
I think there are a couple of good movies showing at the moment, so it is worth a try..
Dendy Cinemas are present in Canberra, Brisbane & Sydney.