LEGO DC Batman Batwing and The Riddler Heist 76120 + Batsub and the Underwater Clash 76116 ($41.98 40% off)

Amazon is running a promotion on select LEGO sets (spend $50 get $10 off AT CHECKOUT). The applicable sets are constantly changing over the last couples days: HERE
LEGO DC Batman: Batman Batsub and the Underwater Clash 76116 Building Kit, 2019 (174 Pieces) $15.99
LEGO DC Batman: Batman Batwing and The Riddler Heist 76120 Building Kit, New 2019 (489 Pieces) $35.99
Another good option is the Batwing set + Infinity War The Hulkbuster Smash-Up 76104 which comes out to $45.96 or 43% off