Caesars noon for $330, Venetian noon for $550, Wynn noon on Friday only for $530, Bellagio 2pm for $1060. Visit
www.allvegaspoker.com and click on "tournament" and look there for details. Though I think the starting chip count they show for Wynn is out-of-date...I haven't played it since it supposedly increased but I was told they're now giving 5000 starting instead of 3000.
I'd pick Caesars, myself. Don't make dinner plans if you're going to play any of these; you will be doing nothing but one poker tourney all day if you do well.
A bit more affordable but not as nice a structure would be the Sahara 7pm or 11pm and the Orleans 7pm.