At Target, when you add a qualifying toy or doll to your cart, you'll get 40% off a second of equal or lesser value. That beats last month's mention of buy one LEGO set to get 30% off a second and is the best such offer we've seen from Target since our December mention of buy one get one for 50% off a similar selection of toys. Shipping starts around $5. A couple best bets, with prices before discount:
Target offers the Lego Movie Lord Business' Evil Lair, model no. 70809, for $54.99 with free shipping. (Amazon has it for the same price.) That's the lowest total price we could find by $4. It features office, think tank, Kragle, glue holder, TV studio with camera, sofa, "Where Are My Pants?" sign, giant glue tube, and six mini-figures.
Target offers the LEGO Marvel Super Heroes Spider-Cycle Chase, model no. 76004, for $13.99. (Amazon has it for Prime members for the same price.) Opt for free in-store pickup to avoid the $5.43 shipping charge. That's $6 less than the lowest pickup price we could find. This 237-piece set comes with three minifigures: Spider-Man, Venom, and Nick Fury.
Update: It's currently out of stock for pickup at Target; however, Amazon still offers it for $13.99 with free shipping for Prime members.