China Travel Service sometimes have specials for round trip ticket plus one night hotel for about $400 per person, thats if you wish to stay the night... like if you go in the evening, check out the Venetian or other casino. Then sleep and go to Senada Square and see the ruins and stuff the next day before coming back.
I went in january... they put us in Hotel Tapia, which is pretty nice and it's close to the venetian. MGM grand is pretty cool too.