Need 4 songs mixed and mastered for EP

Hi there, my band are looking to record a 4 song EP early next year and we're looking for an engineer to mix and master our project. We are an alternative rock band, who draws influence from Foo Fighters, 30 Seconds to Mars, and Biffy Clyro. We're a young band, so can't afford anything crazy, $500 is our limit for mixing and mastering this project. Here is a link to our soundcloud: Thank you