It's really just another way of saying that something's cheap, and generally used in reference to something else: "You could stay at that hotel, but this one is a fraction of the price."

The missing part is "the price of *what*?" However, we may know *what* is meant in context. It basically means hotels are much cheaper, but without seeing the paragraph I can't tell you compared to what.

It may mean that it is heavily discounted or just a very low price. We say 'a fraction of the proce' a lot