That's very good work, Luxxeon.  My only crits are that the rocks look too clean, and I feel you could have added some blades of grass randomly in the dirt, and maybe on the outer rim of the object.  Even just some low poly strips or something to simulate grass. 

A little word of advice:  if you're going to keep offering this level of quality on Turbosquid, you better think about charging something for them.  Even if it's a dollar (American).  Otherwise, you might get booted from there.