The great thing about horror movies as a genre is just how accessible they are to filmmakers, with some iconic horror films being made for pennies on the dollar. Compared to many other films, horror movies are often able to see an absurdly high return on investment thanks to the genre's in-built audience, who are frequently more willing to hear out new ideas and concepts. In fact, some of the greatest horror movies of all time were made with shockingly small budgets.