Walmart has the LEGO Ideas 21309 NASA Apollo Saturn V set for $90 with free shipping. Features set includes over 1,900 pieces, comes with 3 astronaut micro-figures, recommended for ages 14 years & up.
Ends 10/1. Amazon has the Meigo 117-Piece STEM Building Set for $36 - $18 off with coupon 50KEDURE = $18 with free shipping. Features 114 blocks, 2 ratchets, and 1 plastic power drill, instructions for building several different shapes, lead, BPA, and pthalate-free.
Has good Amazon Reviews.
Amazon has the CubicFun 3D Puzzle New York Cityline Kit (MC255h-NEW) for $18 - 20% off coupon (clip extra savings coupon applied at checkout) = $14 with free shipping on $25+ or with Prime. Features 123-pieces and made for 8 years and up.
Has excellent Amazon Reviews.