Here are some images of vampire characters and their costumes. The smallest image is Vlad the Impaler, whom Dracula's character is based on. In his portrait, he is depicted as having long black hair and black medieval clothing. When audiences watch typical vampire movies, they resemble this image. The closest to Vlad the Impaler costume wise is Nosferatu. He wears a very similar hat to Vlad the Impaler (in the Royal family of romania in the 15th Century, the hat he is wearing was instead of a crown). He also is wearing a luxurious coat with brass buttons, like Vlad the Impaler. Additionally, we can see the Vlad isn't wearing any black clothing, but has black hair. Maybe the typical black clothing worn by vampires is to make up for that or resemble the same meaning of evilness. The fact that they both lived in castles is also a huge resemblance. Lastly, the star in the middle of Vlad's "crown" is usually seen as a crest worn around their necks. This is a subtle way of saying they're the same person or descendent without them looking identical. In addition, we can see Vlad is also wearing a fur cape. Maybe this is where vampires originally get their caped look from. 
In our film, our evil Vampire also wears a hat; though a modern looking hat, this puts a modern twist on the legend to appeal more to a younger audience. The black clothing is also included in his costume; however he also wears an evening shirt and black, shiny, pointy business man like shoes. The luxurious, royal look gives the vampires a sense of power, like the fact that Vlad was a royal, did.
