depends on what kind of soil and what they can do with it. A few years ago there were some nearby marina developments/swampy land industrial sites accepting clean fill for free, so these guys were dumping there and charging a lower rate. Even better is when an excavator needs some fill for another job, and takes your dirt to use there (essentially selling your waste to the next guy and making $). So without knowing your area, I have no idea, just giving you a little insight into how things work behind the scenes where I live, and the "it depends" answer.
cheerios