Speak of the devil... I just went to Vegas last weekend!
I stayed at the Excalibur for $195.00 a night. That is 5 bucks less than 200
. It was one of the cheapest around. It was nice too. Though you will probably only use the room to shower, change clothes, and the occasional 3 hour nap!
I guess try the hotels.com or something similar. Also, try calling the hotel directly and speaking to them, sometimes they will give you a break.
If you plan on gambling and do well/awful you may be able to get your room compted... one on my buddies got his compted. It is definitely worth signing up for the card/account so they can track you.
Also, if you go down to freemont street check out the golden nugget. They have a shark tank in their swimming pool with a water slide though it!!! It is awesome. Also the min bets are cheaper on freemont street. If you staying on the strip it is about a 25 dollar taxi ride or a 2 dollar bus ride (though the bus takes about twice the amount of time to get there, but you save 20 bucks).
Most of all, have fun!!!!