As Doppy said, most Vegas resorts do not allow check-in or check-out on Saturday. Try again once you're there.

Why the LVH as a backup? It's a mediocre hotel way out of the way. Bally's is just as good as the Hilton, right across the street from Bellagio, and Orbitz has it for $59/night for the whole time you are there.

QL