If you buy something in a sale, then you pay the sale price. If you buy an item at full price, when it is available elsewhere at a higher price you make a profit
You've mixed up your words a little there, however, you don't make a profit, you spend less.Although I did hear a good joke...
I bought a teddy bear for £10 and named it Mohammed. I then sold it for £20... Did I make a prophet?