Stumbled upon this last night when ordering a family box via the touch screen kiosk @ Wetherill Park mcDonalds
Obviously a glitch but i was able to swap the small fries ($1 value) with the NEW loaded fries ($5 value) and also upgrade to a water bottle at no extra cost. Saved around $20 when compared to buying each individual item separately!
They still charged for big mac sauce so it wasn't all free :)
Beef Value Box NSW/ACT & 1030am - 11pm only.
Water costs more than softdrink?