Low Budget Trailers

There are many low budget trailers out there, which prove that trailers don't always have to consist of money to be spent on them.
When it comes to looking at trailers Shannon and I are trying to keep them to the horror genre as that is the specific genre we are aiming to create for our own project.
An example of a low budget horror trailer is paranormal activity.
They have done the whole sequence on a low budget and these are the trailers from 1, 2 and 3. The paranormal activity trailer, I personally feel work really well and don't make them look as if they are low budget. This is what I hope to achieve with my trailer - I do not want it to look cheap!

Paranormal activity 1.

Paranormal Activity 2

Paranormal Activity 3