This week from May 25-31, Toys R Us America stores will be offering a FREE 30302 LEGO Spider-Man Glider when you buy ANY LEGO construction set. Valid in-stores only while supplies last.
Apparently, there’s no threshold mentioned so you can literally buy another polybag ($3.99-$4.99) and get the Spider-Man Glider set for free. Not bad as that works out to be 40-50% off! Thanks to forum member Nepenthe7 for the heads up.