Amazon offers Lionel Mega Tracks Corkscrew Chaos
in Green for $18.81
with free shipping
for Prime members. That's $5 under last week's mention and the lowest price we've seen. (It's the best deal now by $3.) It includes 20 feet of TwisTrack and 55 construction pieces.
Depending on your location, this may still be available for expected delivery by Christmas via Prime or upgraded shipping options.