This must depend on your
WalMart. I've never seen
Lego's clearanced anywhere that I've lived. I've learned...my kids build the spendy sets, then immediately tear them apart, never to be built again. I no longer buy sets.
Matter of fact, most of the legos my son gets now are from the Lego store...the buckets you can fill. If you keep the bucket and take it back to refill they give you a .50 discount.
I do see sales at the Lego store occasionally. All we have is an outlet...not the real deal...but even a few dollars off a set is better than nothing.