In most cases there are only a very few items in the store that is stating up to 50% off ...usually very few and probably some backstock items that were not selling well.

THEY MUST ALSO STATE HOW MANY ITEMS ARE ACTUALLY 50% OFF

Another sales gimmick stating on the item box up to 25% off but in some cases the quantity in the box has been reduced to about 25% less without most shoppers realising thinking it's a bargain buy 

ALWAYS CHECK QUANTITY