Kmart offers the LEGO Super Heroes Rhino and Sandman Set, model no. 76037, for $31.99. Opt for in-store pickup to avoid the $5.75 shipping fee. That's the lowest price we could find by $8. It includes Rhino, Spider-Man, Iron Spider, and Sandman minifigures.
Of note, Shop Your Way Rewards members will earn a Kmart credit with this purchase and may be eligible for additional credits and discounts.