Amazon has the LEGO DUPLO Number Train 10558 marked down to $13.97 from $19.99.
Keep in mind that Amazon prices flip fast. Be sure to check current pricing before purchasing.
They also have the LEGO DUPLO My First Zoo 6136 for $13.97, down from $19.99.
LEGO Bricks and More DUPLO My First Build 4631 for $17.42, down from $24.99.