What is the difference between a "buy one, get one free" deal and a "half-price" sale? For units purchased between 0 and 1 unit, a "buy one, get one free" deal (Click to select) , and a half-price sale (Click to select) . For units purchased between 1 and 2 units, a "buy one, get one free" deal (Click to select) , and a half-price sale (Click to select)