Construction Vehicles for Sale

One time on my way home from a trip we passed a construction site, and to my amazement there was a gigantic piece of machinery called an earthmover on sale right there by the road. Frankly I had no urge to yell stop the car, that's just what I always wanted a gigantic piece of machinery I would never use...shouldn't it be advertised in a construction magazine, and not on the side of a highway? And another thing, why would a construction company sell a big thing like that, I mean there's got to be something wrong with it.