If you're USAA Hertz has a nice discount and you can also register to become a gold member for an extra discount on top of that and so you can start racking up points.
I often get the best rate from dollar.com. See their city specials for the best bargains. I paid less than $150/week after all fees and taxes for a full size in Vegas. They beat Costco by 30%.
Keep checking for lower rates. Don't prepay. I check with Expedia then go to the direct website for the company that had a good price, they are sometimes cheaper. Join their "club' you may get a small discount. Say no to all the extras. Use Google for some discount codes. Bring your own Sunpass for the tolls and check on how to use with a rental.