My local Walmart has massive LEGO for clearance, include series of City, Superhero, Star wars, and ninja.
Since I found 2 Walmart stores in my area (Southern IL) are having all those LEGOs for clearance, I believe this is a seasonal clearance event. Go check your local Walmart for stock availability. The clearance items are put together with the regular priced items, so look for the yellow Tag.
Attachments are the pictures I took in store.
Some of the noticeable huge discount include:
Volcano Exploration, Now $59, MSRP $119. (I bought this one)
Bulldozer Break-in, Now $40, MSRP $68.
Airport VIP Service, Now $30, MSPR $42.
Volcano Supply Helicopter, Now $30, MSRP $46.
Killer Croc Tail Gator, Now $45, MSRP $58.
Batman Killer Croc Sewer Smash, Now $49, MSRP $64.
Poe X-Wing, Now $49
Rathtar Escape, Now $54
Clone Turbo Tank, Now $69, MSRP $99
Rex ATTA $69, MSRP $115.
Krennic's Shuttle, Now $64, MSRP $73.