I was the National Museum of Singapore for the
Egyptian exhibition and had some time to spare after that, so I went to the
Bag exhibition upstairs, which featured paper and plastic bags in Singapore throughout the years.
And of course, even while I was there to do a project on another module, I was still looking out for lexical observations for this module (Prof, are you reading this? ;D )
And I found this bag that had me raising an eyebrow.

No, I'm not talking about their fashion :p I was referring to this:

It's a redundant thing to say isn't it! Cheap sale! It's like saying tall skyscraper, or dark night. It's already implied in the noun!
But perhaps the store was right in saying this. I surfed
Merriam Webster and the definitions in points 1 and 4 were different:
1) the act of selling
4) a selling of goods at bargain prices
So if the store was referring to the first definition, then their use of "cheap sale" could be justified. Though I find it abit iffy that they would describe a "sale" as "cheap". I would rather if they had said "cheap prices" or "cheap clothes", but that's just me :D