Target offers the LEGO Technic Class Xerion 500 Trac VC Tractor, model no. 42054, for $129.99. Add it to your cart to drop it to $104.99. With free shipping, that's $25 below our October mention and the best price we've seen. (It's a current low by $25, although most merchants charge at least $180.) This 1,977-piece kit includes a LEGO Power Functions motor and can be configured to carry out a number of motorized functions.