Today's throwback is a memory I have when I started as a TA in the mid-90's of special AC economy NITE fares for the redeye YEG-YYZ that left around 1AM daily and was cheaper than all other daytime flights by IIRC $50 - $75 or thereabouts. Discounted economy Ticket totals - without the myriad of surcharges and fees - were in the $180 - $240 range roundtrip, again IIRC.
Ah, those were the days...