Mikey, see if your hotel has an off-airport rental company in-house--many do, especially the resorts. If not, I could get you phone numbers for a couple. There are also some el-cheapos near the airport, like ACE and Resort.
Another, more fun strategy would be to rent in Vegas, where they are usually cheap, and drive down--maybe 5 hours on a good day. Then, plan some fun time on the front or back end.
JP