You should be able to pick up a room in July at a very reasonable rate (without being comped)

Unless you play big or win big, you will not be comped for your room. However, sign up for all the slot clubs at every casino you visit! Why? Besides picking up something you can trade for chips and other casino stuff later, the casinos will send you great deals to entice you to come back next time.

Second, I would buy a good book on playing video poker. Video poker is one of the few games that can have positive return (paying over 100%).

If you're planning to go back within a year's time, go to the Stratosphere and play their video poker machines (marked 100% or higher). If you sign up for their slot club, they will give you a percentage back (I think it was 10%) in the form of a check for your next visit to Vegas. I played for 2 hours on a $100, won money, and when I got back home there was a check for $97 waiting for me! The Stratosphere is not the best casino (the location is between the strip and downtown) but free money is free money!