Walmart offers the K'NEX Raptor's Revenge Roller Coaster Building Set
, model no. 51432, for $17.88
. Opt for in-store pickup
to avoid the $4.97 shipping charge. That's tied with our mention from a week ago, $17 off list, and the lowest price we could find. It includes over 19 feet in track, 617 pieces, and a motorized coaster.