Eric, Joe is correct aboot harrahs, when the rates are that low, the group rate is not much better.
The group rate does allow for them to estimate how many rooms you will need, and they also try to get everybody on the same floor/tower if everyone books the same type of room.
They have nicer rooms that cost more and sometimes what they will do is give you the nicer rooms, for the cost of the basic room, so while it doesnt seem like your saving much money, you are because of the nicer room.
Last Mojave they already had a couple groups on the same night so the deal was not that good and we didn't get a room upgrade so I didn't bother with the group rate, but its worth a shot.
Sent from my rooftop tent while stargazing