Toys’R’Us stores are offering a free polybag 30302 Spider-Man Glider free with any LEGO Construction set purchase. I couldn’t see any rule for a minimum dollar amount so I’m unsure if there is one. The ad specifically says “construction” so no games or display cases or any other non-construction LEGO items will qualify. You can also outright buy the polybag set for a mere $3.99. The free offer is valid from May 25 through May 31 or while supplies last. They are also advertising the new Ultra Agents theme as being available but as always your mileage may vary.
