Book Trailers are the easiest way to give potential readers of your work a taste of what your book is like. Better than just a cover and some marketing copy, you can give your readers an idea of the tone, style, and themes in your book. They're dynamic advertisements for your book that are always available, linkable days, months, years after they've been posted.
My book trailers have been nominated for awards and have proven to be effective and popular. I'd be happy to discuss the budget and possibilities with you. Here are a few samples of my work:
The Electric Church in One Minute was nominated for a Moby award in 2010 for Best Low Budget/Indie Book Trailer
Codename: Dancer was noted by the Happy Ever After blog on USA Today