Figure up your hours spent x your hourly rate. I wouldn't hit them with the same price again, I think it's rude. Sure, it's a pita that they are jerking you around a little, but they are the ones paying you. As you stated before, you made good money the first time. Price it so that you make good money this time too. I would probably charge about $1000 and 2 of my guys would have it done before lunch. Throw in sod installation quote for another $800 or so.
Walker, Toro, Stihl